diff --git a/.changeset/fast-parser-hotpaths.md b/.changeset/fast-parser-hotpaths.md
new file mode 100644
index 0000000000..f442e2435f
--- /dev/null
+++ b/.changeset/fast-parser-hotpaths.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+perf: optimize parser hot paths for faster compilation
diff --git a/.changeset/rotten-taxes-float.md b/.changeset/rotten-taxes-float.md
new file mode 100644
index 0000000000..4c04f78324
--- /dev/null
+++ b/.changeset/rotten-taxes-float.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: more efficient effect scheduling
diff --git a/.changeset/vast-ties-wash.md b/.changeset/vast-ties-wash.md
new file mode 100644
index 0000000000..39c14b4a17
--- /dev/null
+++ b/.changeset/vast-ties-wash.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+chore: null out current_batch before committing branches
diff --git a/.github/workflows/pkg.pr.new.yml b/.github/workflows/pkg.pr.new.yml
index e7cc1facad..cd3df32064 100644
--- a/.github/workflows/pkg.pr.new.yml
+++ b/.github/workflows/pkg.pr.new.yml
@@ -10,6 +10,10 @@ on:
         description: 'Commit SHA to build'
         required: true
         type: string
+      pr:
+        description: 'PR number to comment on'
+        required: true
+        type: number
 
 permissions: {}
 
@@ -127,26 +131,16 @@ jobs:
               return;
             }
 
-            const { data: pulls } = await github.rest.repos.listPullRequestsAssociatedWithCommit({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              commit_sha: '${{ inputs.sha }}',
-            });
-
-            const open = pulls.filter(p => p.state === 'open');
-
-            if (open.length === 0) {
-              core.setFailed(`No open PR found for commit ${{ inputs.sha }}`);
-              return;
-            }
-
-            if (open.length > 1) {
-              const nums = open.map(p => `#${p.number}`).join(', ');
-              core.setFailed(`Multiple open PRs found for commit ${{ inputs.sha }}: ${nums}`);
+            // For workflow_dispatch, use the explicitly provided PR number.
+            // We can't use listPullRequestsAssociatedWithCommit because fork
+            // commits don't exist in the base repo, so the API returns nothing.
+            const pr = Number('${{ inputs.pr }}');
+            if (!pr || isNaN(pr)) {
+              core.setFailed('workflow_dispatch requires a valid pr input');
               return;
             }
 
-            core.setOutput('number', open[0].number);
+            core.setOutput('number', pr);
 
       - name: Post or update comment
         uses: actions/github-script@v8
diff --git a/documentation/docs/05-special-elements/01-svelte-boundary.md b/documentation/docs/05-special-elements/01-svelte-boundary.md
index 40e8d144e1..e1ad00a50b 100644
--- a/documentation/docs/05-special-elements/01-svelte-boundary.md
+++ b/documentation/docs/05-special-elements/01-svelte-boundary.md
@@ -102,3 +102,40 @@ If an `onerror` function is provided, it will be called with the same two `error
 ```
 
 If an error occurs inside the `onerror` function (or if you rethrow the error), it will be handled by a parent boundary if such exists.
+
+## Using `transformError`
+
+By default, error boundaries have no effect on the server — if an error occurs during rendering, the render as a whole will fail.
+
+Since 5.51 you can control this behaviour for boundaries with a `failed` snippet, by calling [`render(...)`](imperative-component-api#render) with a `transformError` function.
+
+> [!NOTE] If you're using Svelte via a framework such as SvelteKit, you most likely don't have direct access to the `render(...)` call — the framework must configure `transformError` on your behalf. SvelteKit will add support for this in the near future, via the [`handleError`](../kit/hooks#Shared-hooks-handleError) hook.
+
+The `transformError` function must return a JSON-stringifiable object which will be used to render the `failed` snippet. This object will be serialized and used to hydrate the snippet in the browser:
+
+```js
+// @errors: 1005
+import { render } from 'svelte/server';
+import App from './App.svelte';
+
+const { head, body } = await render(App, {
+	transformError: (error) => {
+		// log the original error, with the stack trace...
+		console.error(error);
+
+		// ...and return a sanitized user-friendly error
+		// to display in the `failed` snippet
+		return {
+			message: 'An error occurred!'
+		};
+	};
+});
+```
+
+If `transformError` throws (or rethrows) an error, `render(...)` as a whole will fail with that error.
+
+> [!NOTE] Errors that occur during server-side rendering can contain sensitive information in the `message` and `stack`. It's recommended to redact these rather than sending them unaltered to the browser.
+
+If the boundary has an `onerror` handler, it will be called upon hydration with the deserialized error object.
+
+The [`mount`](imperative-component-api#mount) and [`hydrate`](imperative-component-api#hydrate) functions also accept a `transformError` option, which defaults to the identity function. As with `render`, this function transforms a render-time error before it is passed to a `failed` snippet or `onerror` handler.
diff --git a/documentation/docs/05-special-elements/03-svelte-document.md b/documentation/docs/05-special-elements/03-svelte-document.md
index 43f02865e6..47c382ee56 100644
--- a/documentation/docs/05-special-elements/03-svelte-document.md
+++ b/documentation/docs/05-special-elements/03-svelte-document.md
@@ -10,12 +10,12 @@ title: <svelte:document>
 <svelte:document bind:prop={value} />
 ```
 
-Similarly to `<svelte:window>`, this element allows you to add listeners to events on `document`, such as `visibilitychange`, which don't fire on `window`. It also lets you use [actions](use) on `document`.
+Similarly to `<svelte:window>`, this element allows you to add listeners to events on `document`, such as `visibilitychange`, which don't fire on `window`. It also lets you use [attachments](@attach) on `document`.
 
 As with `<svelte:window>`, this element may only appear the top level of your component and must never be inside a block or element.
 
 ```svelte
-<svelte:document onvisibilitychange={handleVisibilityChange} use:someAction />
+<svelte:document onvisibilitychange={handleVisibilityChange} {@attach someAttachment} />
 ```
 
 You can also bind to the following properties:
diff --git a/documentation/docs/07-misc/03-typescript.md b/documentation/docs/07-misc/03-typescript.md
index 49ecd8adb5..899849473c 100644
--- a/documentation/docs/07-misc/03-typescript.md
+++ b/documentation/docs/07-misc/03-typescript.md
@@ -75,7 +75,7 @@ In both cases, a `svelte.config.js` with `vitePreprocess` will be added. Vite/Sv
 
 ### Other build tools
 
-If you're using tools like Rollup or Webpack instead, install their respective Svelte plugins. For Rollup that's [rollup-plugin-svelte](https://github.com/sveltejs/rollup-plugin-svelte) and for Webpack that's [svelte-loader](https://github.com/sveltejs/svelte-loader). For both, you need to install `typescript` and `svelte-preprocess` and add the preprocessor to the plugin config (see the respective READMEs for more info). If you're starting a new project, you can also use the [rollup](https://github.com/sveltejs/template) or [webpack](https://github.com/sveltejs/template-webpack) template to scaffold the setup from a script.
+If you're using tools like Rollup or Webpack instead, install their respective Svelte plugins. For Rollup that's [rollup-plugin-svelte](https://github.com/sveltejs/rollup-plugin-svelte) and for Webpack that's [svelte-loader](https://github.com/sveltejs/svelte-loader). For both, you need to install `typescript` and `svelte-preprocess` and add the preprocessor to the plugin config (see the respective READMEs for more info).
 
 > [!NOTE] If you're starting a new project, we recommend using SvelteKit or Vite instead
 
diff --git a/documentation/docs/07-misc/07-v5-migration-guide.md b/documentation/docs/07-misc/07-v5-migration-guide.md
index 5a80734b7a..564c707fd2 100644
--- a/documentation/docs/07-misc/07-v5-migration-guide.md
+++ b/documentation/docs/07-misc/07-v5-migration-guide.md
@@ -682,6 +682,24 @@ Previously, Svelte employed a very complicated algorithm to determine if whitesp
 
 - Whitespace between nodes is collapsed to one whitespace
 - Whitespace at the start and end of a tag is removed completely
+
+  This new behavior is slightly different from native HTML rendering. For example, `<p>foo<span> - bar</span></p>` will render:
+
+  - `foo - bar` in HTML
+  - `foo- bar` in Svelte 5
+
+  You can reintroduce the missing space by moving it outside the `<span>`...
+  
+  ```svelte
+  <p>foo <span>- bar</span></p>
+  ```
+
+...or, if necessary for styling reasons, including it as an expression:
+
+```svelte
+  <p>foo<span>{' '}- bar</span></p>
+```
+
 - Certain exceptions apply such as keeping whitespace inside `pre` tags
 
 As before, you can disable whitespace trimming by setting the `preserveWhitespace` option in your compiler settings or on a per-component basis in `<svelte:options>`.
diff --git a/documentation/docs/98-reference/.generated/client-errors.md b/documentation/docs/98-reference/.generated/client-errors.md
index 8601a728a7..7fccac5808 100644
--- a/documentation/docs/98-reference/.generated/client-errors.md
+++ b/documentation/docs/98-reference/.generated/client-errors.md
@@ -62,6 +62,14 @@ Keyed each block has duplicate key at indexes %a% and %b%
 Keyed each block has duplicate key `%value%` at indexes %a% and %b%
 ```
 
+### each_key_volatile
+
+```
+Keyed each block has key that is not idempotent — the key for item at index %index% was `%a%` but is now `%b%`. Keys must be the same each time for a given item
+```
+
+The key expression in a keyed each block must return the same value when called multiple times for the same item. Using expressions like `[item.a, item.b]` creates a new array each time, which will never be equal to itself. Instead, use a primitive value or create a stable key like `item.a + '-' + item.b`.
+
 ### effect_in_teardown
 
 ```
diff --git a/documentation/docs/98-reference/.generated/server-errors.md b/documentation/docs/98-reference/.generated/server-errors.md
index c98756afec..0ee6fd0614 100644
--- a/documentation/docs/98-reference/.generated/server-errors.md
+++ b/documentation/docs/98-reference/.generated/server-errors.md
@@ -16,6 +16,14 @@ Encountered asynchronous work while rendering synchronously.
 
 You (or the framework you're using) called [`render(...)`](svelte-server#render) with a component containing an `await` expression. Either `await` the result of `render` or wrap the `await` (or the component containing it) in a [`<svelte:boundary>`](svelte-boundary) with a `pending` snippet.
 
+### dynamic_element_invalid_tag
+
+```
+`<svelte:element this="%tag%">` is not a valid element name — the element will not be rendered
+```
+
+The value passed to the `this` prop of `<svelte:element>` must be a valid HTML element, SVG element, MathML element, or custom element name. A value containing invalid characters (such as whitespace or special characters) was provided, which could be a security risk. Ensure only valid tag names are passed.
+
 ### html_deprecated
 
 ```
diff --git a/package.json b/package.json
index b305ce9cd1..34079f43cf 100644
--- a/package.json
+++ b/package.json
@@ -27,12 +27,12 @@
   },
   "devDependencies": {
     "@changesets/cli": "^2.29.8",
-    "@sveltejs/eslint-config": "^8.3.5",
+    "@eslint/js": "^10.0.0",
+    "@sveltejs/eslint-config": "^9.0.0",
     "@svitejs/changesets-changelog-github-compact": "^1.1.0",
     "@types/node": "^20.11.5",
     "@types/picomatch": "^4.0.2",
     "@vitest/coverage-v8": "^2.1.9",
-    "@eslint/js": "^10.0.0",
     "eslint": "^10.0.0",
     "eslint-plugin-lube": "^0.5.1",
     "eslint-plugin-svelte": "^3.15.0",
@@ -42,15 +42,8 @@
     "prettier-plugin-svelte": "^3.4.0",
     "svelte": "workspace:^",
     "typescript": "^5.5.4",
-    "typescript-eslint": "^8.55.0",
+    "typescript-eslint": "^8.56.0",
     "v8-natives": "^1.2.5",
     "vitest": "^2.1.9"
-  },
-  "pnpm": {
-    "peerDependencyRules": {
-      "allowedVersions": {
-        "eslint": "10"
-      }
-    }
   }
 }
diff --git a/packages/svelte/CHANGELOG.md b/packages/svelte/CHANGELOG.md
index 4e4f4f6088..c7b7ea7f58 100644
--- a/packages/svelte/CHANGELOG.md
+++ b/packages/svelte/CHANGELOG.md
@@ -1,5 +1,101 @@
 # svelte
 
+## 5.53.5
+
+### Patch Changes
+
+- fix: escape `innerText` and `textContent` bindings of `contenteditable` ([`0df5abcae223058ceb95491470372065fb87951d`](https://github.com/sveltejs/svelte/commit/0df5abcae223058ceb95491470372065fb87951d))
+
+- fix: sanitize `transformError` values prior to embedding in HTML comments ([`0298e979371bb583855c9810db79a70a551d22b9`](https://github.com/sveltejs/svelte/commit/0298e979371bb583855c9810db79a70a551d22b9))
+
+## 5.53.4
+
+### Patch Changes
+
+- fix: set server context after async transformError ([#17799](https://github.com/sveltejs/svelte/pull/17799))
+
+- fix: hydrate if blocks correctly ([#17784](https://github.com/sveltejs/svelte/pull/17784))
+
+- fix: handle default parameters scope leaks ([#17788](https://github.com/sveltejs/svelte/pull/17788))
+
+- fix: prevent flushed effects from running again ([#17787](https://github.com/sveltejs/svelte/pull/17787))
+
+## 5.53.3
+
+### Patch Changes
+
+- fix: render `:catch` of `#await` block with correct key ([#17769](https://github.com/sveltejs/svelte/pull/17769))
+
+- chore: pin aria-query@5.3.1 ([#17772](https://github.com/sveltejs/svelte/pull/17772))
+
+- fix: make string coercion consistent to `toString` ([#17774](https://github.com/sveltejs/svelte/pull/17774))
+
+## 5.53.2
+
+### Patch Changes
+
+- fix: update expressions on server deriveds ([#17767](https://github.com/sveltejs/svelte/pull/17767))
+
+- fix: further obfuscate `node:crypto` import from overzealous static analysis ([#17763](https://github.com/sveltejs/svelte/pull/17763))
+
+## 5.53.1
+
+### Patch Changes
+
+- fix: handle shadowed function names correctly ([#17753](https://github.com/sveltejs/svelte/pull/17753))
+
+## 5.53.0
+
+### Minor Changes
+
+- feat: allow comments in tags ([#17671](https://github.com/sveltejs/svelte/pull/17671))
+
+- feat: allow error boundaries to work on the server ([#17672](https://github.com/sveltejs/svelte/pull/17672))
+
+### Patch Changes
+
+- fix: use TrustedHTML to test for customizable `<select>` support, where necessary ([#17743](https://github.com/sveltejs/svelte/pull/17743))
+
+- fix: ensure head effects are kept in the effect tree ([#17746](https://github.com/sveltejs/svelte/pull/17746))
+
+- chore: deactivate current_batch by default in unset_context ([#17738](https://github.com/sveltejs/svelte/pull/17738))
+
+## 5.52.0
+
+### Minor Changes
+
+- feat: support TrustedHTML in `{@html}` expressions ([#17701](https://github.com/sveltejs/svelte/pull/17701))
+
+### Patch Changes
+
+- fix: repair dynamic component truthy/falsy hydration mismatches ([#17737](https://github.com/sveltejs/svelte/pull/17737))
+
+- fix: re-run non-render-bound deriveds on the server ([#17674](https://github.com/sveltejs/svelte/pull/17674))
+
+## 5.51.5
+
+### Patch Changes
+
+- fix: check to make sure `svelte:element` tags are valid during SSR ([`73098bb26c6f06e7fd1b0746d817d2c5ee90755f`](https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f))
+
+- fix: misc option escaping and backwards compatibility ([#17741](https://github.com/sveltejs/svelte/pull/17741))
+
+- fix: strip event handlers during SSR ([`a0c7f289156e9fafaeaf5ca14af6c06fe9b9eae5`](https://github.com/sveltejs/svelte/commit/a0c7f289156e9fafaeaf5ca14af6c06fe9b9eae5))
+
+- fix: replace usage of `for in` with `for of Object.keys` ([`f89c7ddd7eebaa1ef3cc540400bec2c9140b330c`](https://github.com/sveltejs/svelte/commit/f89c7ddd7eebaa1ef3cc540400bec2c9140b330c))
+
+- fix: always escape option body in SSR ([`f7c80da18c215e3727c2a611b0b8744cc6e504c5`](https://github.com/sveltejs/svelte/commit/f7c80da18c215e3727c2a611b0b8744cc6e504c5))
+
+- chore: upgrade `devalue` ([#17739](https://github.com/sveltejs/svelte/pull/17739))
+
+## 5.51.4
+
+### Patch Changes
+
+- chore: proactively defer effects in pending boundary ([#17734](https://github.com/sveltejs/svelte/pull/17734))
+
+- fix: detect and error on non-idempotent each block keys in dev mode ([#17732](https://github.com/sveltejs/svelte/pull/17732))
+
 ## 5.51.3
 
 ### Patch Changes
diff --git a/packages/svelte/messages/client-errors/errors.md b/packages/svelte/messages/client-errors/errors.md
index bedf6db0a5..3f20cb989d 100644
--- a/packages/svelte/messages/client-errors/errors.md
+++ b/packages/svelte/messages/client-errors/errors.md
@@ -42,6 +42,12 @@ See the [migration guide](/docs/svelte/v5-migration-guide#Components-are-no-long
 
 > Keyed each block has duplicate key `%value%` at indexes %a% and %b%
 
+## each_key_volatile
+
+> Keyed each block has key that is not idempotent — the key for item at index %index% was `%a%` but is now `%b%`. Keys must be the same each time for a given item
+
+The key expression in a keyed each block must return the same value when called multiple times for the same item. Using expressions like `[item.a, item.b]` creates a new array each time, which will never be equal to itself. Instead, use a primitive value or create a stable key like `item.a + '-' + item.b`.
+
 ## effect_in_teardown
 
 > `%rune%` cannot be used inside an effect cleanup function
diff --git a/packages/svelte/messages/server-errors/errors.md b/packages/svelte/messages/server-errors/errors.md
index fd4c17e2a7..533e5405ed 100644
--- a/packages/svelte/messages/server-errors/errors.md
+++ b/packages/svelte/messages/server-errors/errors.md
@@ -10,6 +10,12 @@ Some platforms require configuration flags to enable this API. Consult your plat
 
 You (or the framework you're using) called [`render(...)`](svelte-server#render) with a component containing an `await` expression. Either `await` the result of `render` or wrap the `await` (or the component containing it) in a [`<svelte:boundary>`](svelte-boundary) with a `pending` snippet.
 
+## dynamic_element_invalid_tag
+
+> `<svelte:element this="%tag%">` is not a valid element name — the element will not be rendered
+
+The value passed to the `this` prop of `<svelte:element>` must be a valid HTML element, SVG element, MathML element, or custom element name. A value containing invalid characters (such as whitespace or special characters) was provided, which could be a security risk. Ensure only valid tag names are passed.
+
 ## html_deprecated
 
 > The `html` property of server render results has been deprecated. Use `body` instead.
diff --git a/packages/svelte/package.json b/packages/svelte/package.json
index e9f4713d1c..d87bbab694 100644
--- a/packages/svelte/package.json
+++ b/packages/svelte/package.json
@@ -2,7 +2,7 @@
   "name": "svelte",
   "description": "Cybernetically enhanced web apps",
   "license": "MIT",
-  "version": "5.51.3",
+  "version": "5.53.5",
   "type": "module",
   "types": "./types/index.d.ts",
   "engines": {
@@ -159,7 +159,7 @@
     "@types/node": "^20.11.5",
     "dts-buddy": "^0.5.5",
     "esbuild": "^0.25.10",
-    "rollup": "^4.22.4",
+    "rollup": "^4.59.0",
     "source-map": "^0.7.4",
     "tinyglobby": "^0.2.12",
     "typescript": "^5.5.4",
@@ -172,10 +172,10 @@
     "@types/estree": "^1.0.5",
     "@types/trusted-types": "^2.0.7",
     "acorn": "^8.12.1",
-    "aria-query": "^5.3.1",
+    "aria-query": "5.3.1",
     "axobject-query": "^4.1.0",
     "clsx": "^2.1.1",
-    "devalue": "^5.6.2",
+    "devalue": "^5.6.3",
     "esm-env": "^1.2.1",
     "esrap": "^2.2.2",
     "is-reference": "^3.0.3",
diff --git a/packages/svelte/src/compiler/legacy.js b/packages/svelte/src/compiler/legacy.js
index b1bbcfcf74..459858fe13 100644
--- a/packages/svelte/src/compiler/legacy.js
+++ b/packages/svelte/src/compiler/legacy.js
@@ -101,7 +101,12 @@ export function convert(source, ast) {
 					},
 					instance,
 					module,
-					css: ast.css ? visit(ast.css) : undefined
+					css: ast.css ? visit(ast.css) : undefined,
+					// put it on _comments not comments because the latter is checked by prettier and then fails
+					// if we don't adjust stuff accordingly in our prettier plugin, and so it would be kind of an
+					// indirect breaking change for people updating their Svelte version but not their prettier plugin version.
+					// We can keep it as comments for the modern AST because the modern AST is not used in the plugin yet.
+					_comments: ast.comments?.length > 0 ? ast.comments : undefined
 				};
 			},
 			AnimateDirective(node) {
diff --git a/packages/svelte/src/compiler/phases/1-parse/index.js b/packages/svelte/src/compiler/phases/1-parse/index.js
index 88b4352e8a..81adbbb555 100644
--- a/packages/svelte/src/compiler/phases/1-parse/index.js
+++ b/packages/svelte/src/compiler/phases/1-parse/index.js
@@ -4,7 +4,6 @@
 // @ts-expect-error acorn type definitions are borked in the release we use
 import { isIdentifierStart, isIdentifierChar } from 'acorn';
 import fragment from './state/fragment.js';
-import { regex_whitespace } from '../patterns.js';
 import * as e from '../../errors.js';
 import { create_fragment } from './utils/create.js';
 import read_options from './read/options.js';
@@ -14,6 +13,25 @@ import * as state from '../../state.js';
 
 const regex_position_indicator = / \(\d+:\d+\)$/;
 
+/** @param {number} cc */
+function is_whitespace(cc) {
+	// fast path for common whitespace
+	if (cc === 32 || (cc <= 13 && cc >= 9)) return true;
+	// rare whitespace — \u00a0, \u1680, \u2000-\u200a, \u2028, \u2029, \u202f, \u205f, \u3000, \ufeff
+	if (cc < 160) return false;
+	return (
+		cc === 160 ||
+		cc === 5760 ||
+		(cc >= 8192 && cc <= 8202) ||
+		cc === 8232 ||
+		cc === 8233 ||
+		cc === 8239 ||
+		cc === 8287 ||
+		cc === 12288 ||
+		cc === 65279
+	);
+}
+
 const regex_lang_attribute =
 	/<!--[^]*?-->|<script\s+(?:[^>]*|(?:[^=>'"/]+=(?:"[^"]*"|'[^']*'|[^>\s]+)\s+)*)lang=(["'])?([^"' >]+)\1[^>]*>/g;
 
@@ -191,22 +209,26 @@ export class Parser {
 			return this.template[this.index] === str;
 		}
 
-		return this.template.slice(this.index, this.index + length) === str;
+		return this.template.startsWith(str, this.index);
 	}
 
 	/**
 	 * Match a regex at the current index
-	 * @param {RegExp} pattern  Should have a ^ anchor at the start so the regex doesn't search past the beginning, resulting in worse performance
+	 * @param {RegExp} pattern  Should have the sticky (`y`) flag so that it only matches at the current index
 	 */
 	match_regex(pattern) {
-		const match = pattern.exec(this.template.slice(this.index));
-		if (!match || match.index !== 0) return null;
+		pattern.lastIndex = this.index;
+		const match = pattern.exec(this.template);
+		if (!match || match.index !== this.index) return null;
 
 		return match[0];
 	}
 
 	allow_whitespace() {
-		while (this.index < this.template.length && regex_whitespace.test(this.template[this.index])) {
+		while (
+			this.index < this.template.length &&
+			is_whitespace(this.template.charCodeAt(this.index))
+		) {
 			this.index++;
 		}
 	}
@@ -282,7 +304,7 @@ export class Parser {
 	}
 
 	require_whitespace() {
-		if (!regex_whitespace.test(this.template[this.index])) {
+		if (!is_whitespace(this.template.charCodeAt(this.index))) {
 			e.expected_whitespace(this.index);
 		}
 
diff --git a/packages/svelte/src/compiler/phases/1-parse/read/script.js b/packages/svelte/src/compiler/phases/1-parse/read/script.js
index db3c50a8d1..65153edfc8 100644
--- a/packages/svelte/src/compiler/phases/1-parse/read/script.js
+++ b/packages/svelte/src/compiler/phases/1-parse/read/script.js
@@ -9,7 +9,7 @@ import { is_text_attribute } from '../../../utils/ast.js';
 import { locator } from '../../../state.js';
 
 const regex_closing_script_tag = /<\/script\s*>/;
-const regex_starts_with_closing_script_tag = /^<\/script\s*>/;
+const regex_starts_with_closing_script_tag = /<\/script\s*>/y;
 
 const RESERVED_ATTRIBUTES = ['server', 'client', 'worker', 'test', 'default'];
 const ALLOWED_ATTRIBUTES = ['context', 'generics', 'lang', 'module'];
diff --git a/packages/svelte/src/compiler/phases/1-parse/read/style.js b/packages/svelte/src/compiler/phases/1-parse/read/style.js
index 4f2db349cd..8cb1d54d54 100644
--- a/packages/svelte/src/compiler/phases/1-parse/read/style.js
+++ b/packages/svelte/src/compiler/phases/1-parse/read/style.js
@@ -2,17 +2,17 @@
 /** @import { Parser } from '../index.js' */
 import * as e from '../../../errors.js';
 
-const REGEX_MATCHER = /^[~^$*|]?=/;
+const REGEX_MATCHER = /[~^$*|]?=/y;
 const REGEX_CLOSING_BRACKET = /[\s\]]/;
-const REGEX_ATTRIBUTE_FLAGS = /^[a-zA-Z]+/; // only `i` and `s` are valid today, but make it future-proof
-const REGEX_COMBINATOR = /^(\+|~|>|\|\|)/;
-const REGEX_PERCENTAGE = /^\d+(\.\d+)?%/;
+const REGEX_ATTRIBUTE_FLAGS = /[a-zA-Z]+/y; // only `i` and `s` are valid today, but make it future-proof
+const REGEX_COMBINATOR = /(\+|~|>|\|\|)/y;
+const REGEX_PERCENTAGE = /\d+(\.\d+)?%/y;
 const REGEX_NTH_OF =
-	/^(even|odd|\+?(\d+|\d*n(\s*[+-]\s*\d+)?)|-\d*n(\s*\+\s*\d+))((?=\s*[,)])|\s+of\s+)/;
+	/(even|odd|\+?(\d+|\d*n(\s*[+-]\s*\d+)?)|-\d*n(\s*\+\s*\d+))((?=\s*[,)])|\s+of\s+)/y;
 const REGEX_WHITESPACE_OR_COLON = /[\s:]/;
-const REGEX_LEADING_HYPHEN_OR_DIGIT = /-?\d/;
+const REGEX_LEADING_HYPHEN_OR_DIGIT = /-?\d/y;
 const REGEX_VALID_IDENTIFIER_CHAR = /[a-zA-Z0-9_-]/;
-const REGEX_UNICODE_SEQUENCE = /^\\[0-9a-fA-F]{1,6}(\r\n|\s)?/;
+const REGEX_UNICODE_SEQUENCE = /\\[0-9a-fA-F]{1,6}(\r\n|\s)?/y;
 const REGEX_COMMENT_CLOSE = /\*\//;
 const REGEX_HTML_COMMENT_CLOSE = /-->/;
 
@@ -28,7 +28,7 @@ export default function read_style(parser, start, attributes) {
 	const content_end = parser.index;
 
 	parser.eat('</style', true);
-	parser.read(/^\s*>/);
+	parser.read(/\s*>/y);
 
 	return {
 		type: 'StyleSheet',
diff --git a/packages/svelte/src/compiler/phases/1-parse/state/element.js b/packages/svelte/src/compiler/phases/1-parse/state/element.js
index d9fe33bbac..a14dd167a5 100644
--- a/packages/svelte/src/compiler/phases/1-parse/state/element.js
+++ b/packages/svelte/src/compiler/phases/1-parse/state/element.js
@@ -2,7 +2,7 @@
 /** @import { Location } from 'locate-character' */
 /** @import { AST } from '#compiler' */
 /** @import { Parser } from '../index.js' */
-import { is_void } from '../../../../utils.js';
+import { is_void, REGEX_VALID_TAG_NAME } from '../../../../utils.js';
 import read_expression from '../read/expression.js';
 import { read_script } from '../read/script.js';
 import read_style from '../read/style.js';
@@ -17,15 +17,25 @@ import { list } from '../../../utils/string.js';
 import { locator } from '../../../state.js';
 import * as b from '#compiler/builders';
 
-const regex_invalid_unquoted_attribute_value = /^(\/>|[\s"'=<>`])/;
-const regex_closing_textarea_tag = /^<\/textarea(\s[^>]*)?>/i;
+const regex_invalid_unquoted_attribute_value = /(\/>|[\s"'=<>`])/y;
+const regex_closing_textarea_tag = /<\/textarea(\s[^>]*)?>/iy;
 const regex_closing_comment = /-->/;
 const regex_whitespace_or_slash_or_closing_tag = /(\s|\/|>)/;
 const regex_token_ending_character = /[\s=/>"']/;
-const regex_starts_with_quote_characters = /^["']/;
-const regex_attribute_value = /^(?:"([^"]*)"|'([^'])*'|([^>\s]+))/;
-const regex_valid_element_name =
-	/^(?:![a-zA-Z]+|[a-zA-Z](?:[a-zA-Z0-9-]*[a-zA-Z0-9])?|[a-zA-Z][a-zA-Z0-9]*:[a-zA-Z][a-zA-Z0-9-]*[a-zA-Z0-9])$/;
+const regex_starts_with_quote_characters = /["']/y;
+const regex_attribute_value = /(?:"([^"]*)"|'([^'])*'|([^>\s]+))/y;
+const regex_doctype_name = /^![a-zA-Z]+$/;
+const regex_namespaced_name = /^[a-zA-Z][a-zA-Z0-9]*:[a-zA-Z][a-zA-Z0-9-]*[a-zA-Z0-9]$/;
+
+/** @param {string} name */
+function is_valid_element_name(name) {
+	// DOCTYPE (e.g. !DOCTYPE)
+	if (regex_doctype_name.test(name)) return true;
+	// svelte:* meta tags (e.g. svelte:element, svelte:head)
+	if (regex_namespaced_name.test(name)) return true;
+	// standard HTML/SVG/MathML elements and custom elements
+	return REGEX_VALID_TAG_NAME.test(name);
+}
 export const regex_valid_component_name =
 	// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Lexical_grammar#identifiers adjusted for our needs
 	// (must start with uppercase letter if no dots, can contain dots)
@@ -134,7 +144,7 @@ export default function element(parser) {
 		e.svelte_meta_invalid_tag(bounds, list(Array.from(meta_tags.keys())));
 	}
 
-	if (!regex_valid_element_name.test(tag.name) && !regex_valid_component_name.test(tag.name)) {
+	if (!is_valid_element_name(tag.name) && !regex_valid_component_name.test(tag.name)) {
 		// <div. -> in the middle of typing -> allow in loose mode
 		if (!parser.loose || !tag.name.endsWith('.')) {
 			const bounds = { start: start + 1, end: start + 1 + tag.name.length };
@@ -392,7 +402,10 @@ export default function element(parser) {
 		// special case
 		element.fragment.nodes = read_sequence(
 			parser,
-			() => regex_closing_textarea_tag.test(parser.template.slice(parser.index)),
+			() => {
+				regex_closing_textarea_tag.lastIndex = parser.index;
+				return regex_closing_textarea_tag.test(parser.template);
+			},
 			'inside <textarea>'
 		);
 		parser.read(regex_closing_textarea_tag);
@@ -400,7 +413,13 @@ export default function element(parser) {
 	} else if (tag.name === 'script' || tag.name === 'style') {
 		// special case
 		const start = parser.index;
-		const data = parser.read_until(new RegExp(`</${tag.name}>`));
+		const close_tag = `</${tag.name}>`;
+		const close_index = parser.template.indexOf(close_tag, parser.index);
+		const data = parser.template.slice(
+			parser.index,
+			close_index === -1 ? parser.template.length : close_index
+		);
+		parser.index = close_index === -1 ? parser.template.length : close_index;
 		const end = parser.index;
 
 		/** @type {AST.Text} */
@@ -499,6 +518,15 @@ function read_static_attribute(parser) {
  * @returns {AST.Attribute | AST.SpreadAttribute | AST.Directive | AST.AttachTag | null}
  */
 function read_attribute(parser) {
+	/** @type {AST.JSComment | null} */
+	// eslint-disable-next-line no-useless-assignment -- it is, in fact, eslint that is useless
+	let comment = null;
+
+	while ((comment = read_comment(parser))) {
+		parser.root.comments.push(comment);
+		parser.allow_whitespace();
+	}
+
 	const start = parser.index;
 
 	if (parser.eat('{')) {
@@ -695,6 +723,50 @@ function read_attribute(parser) {
 	return create_attribute(tag.name, tag.loc, start, end, value);
 }
 
+/**
+ * @param {Parser} parser
+ * @returns {AST.JSComment | null}
+ */
+function read_comment(parser) {
+	const start = parser.index;
+
+	if (parser.eat('//')) {
+		const value = parser.read_until(/\n/);
+		const end = parser.index;
+
+		return {
+			type: 'Line',
+			start,
+			end,
+			value,
+			loc: {
+				start: locator(start),
+				end: locator(end)
+			}
+		};
+	}
+
+	if (parser.eat('/*')) {
+		const value = parser.read_until(/\*\//);
+
+		parser.eat('*/');
+		const end = parser.index;
+
+		return {
+			type: 'Block',
+			start,
+			end,
+			value,
+			loc: {
+				start: locator(start),
+				end: locator(end)
+			}
+		};
+	}
+
+	return null;
+}
+
 /**
  * @param {string} name
  * @returns {any}
@@ -789,7 +861,8 @@ function read_sequence(parser, done, location) {
 
 	/** @param {number} end */
 	function flush(end) {
-		if (current_chunk.raw) {
+		if (end > current_chunk.start) {
+			current_chunk.raw = parser.template.slice(current_chunk.start, end);
 			current_chunk.data = decode_character_references(current_chunk.raw, true);
 			current_chunk.end = end;
 			chunks.push(current_chunk);
@@ -843,7 +916,7 @@ function read_sequence(parser, done, location) {
 				data: ''
 			};
 		} else {
-			current_chunk.raw += parser.template[parser.index++];
+			parser.index++;
 		}
 	}
 
diff --git a/packages/svelte/src/compiler/phases/1-parse/state/tag.js b/packages/svelte/src/compiler/phases/1-parse/state/tag.js
index 138eda8033..d9518c726f 100644
--- a/packages/svelte/src/compiler/phases/1-parse/state/tag.js
+++ b/packages/svelte/src/compiler/phases/1-parse/state/tag.js
@@ -10,7 +10,7 @@ import read_expression, { get_loose_identifier } from '../read/expression.js';
 import { create_fragment } from '../utils/create.js';
 import { match_bracket } from '../utils/bracket.js';
 
-const regex_whitespace_with_closing_curly_brace = /^\s*}/;
+const regex_whitespace_with_closing_curly_brace = /\s*}/y;
 
 const pointy_bois = { '<': '>' };
 
diff --git a/packages/svelte/src/compiler/phases/1-parse/state/text.js b/packages/svelte/src/compiler/phases/1-parse/state/text.js
index d0af3a846a..1eab43081d 100644
--- a/packages/svelte/src/compiler/phases/1-parse/state/text.js
+++ b/packages/svelte/src/compiler/phases/1-parse/state/text.js
@@ -6,12 +6,12 @@ import { decode_character_references } from '../utils/html.js';
 export default function text(parser) {
 	const start = parser.index;
 
-	let data = '';
-
 	while (parser.index < parser.template.length && !parser.match('<') && !parser.match('{')) {
-		data += parser.template[parser.index++];
+		parser.index++;
 	}
 
+	const data = parser.template.slice(start, parser.index);
+
 	/** @type {AST.Text} */
 	parser.append({
 		type: 'Text',
diff --git a/packages/svelte/src/compiler/phases/1-parse/utils/bracket.js b/packages/svelte/src/compiler/phases/1-parse/utils/bracket.js
index 8c69a58c99..63fbc68fb3 100644
--- a/packages/svelte/src/compiler/phases/1-parse/utils/bracket.js
+++ b/packages/svelte/src/compiler/phases/1-parse/utils/bracket.js
@@ -141,13 +141,15 @@ const default_brackets = {
 	'[': ']'
 };
 
+const default_close = new Set(Object.values(default_brackets));
+
 /**
  * @param {Parser} parser
  * @param {number} start
  * @param {Record<string, string>} brackets
  */
 export function match_bracket(parser, start, brackets = default_brackets) {
-	const close = Object.values(brackets);
+	const close = brackets === default_brackets ? default_close : new Set(Object.values(brackets));
 	const bracket_stack = [];
 
 	let i = start;
@@ -162,7 +164,7 @@ export function match_bracket(parser, start, brackets = default_brackets) {
 
 		if (char in brackets) {
 			bracket_stack.push(char);
-		} else if (close.includes(char)) {
+		} else if (close.has(char)) {
 			const popped = /** @type {string} */ (bracket_stack.pop());
 			const expected = /** @type {string} */ (brackets[popped]);
 
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/AssignmentExpression.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/AssignmentExpression.js
index 49a284d12b..e6a1a86aa8 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/AssignmentExpression.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/AssignmentExpression.js
@@ -68,35 +68,52 @@ function build_assignment(operator, left, right, context) {
 		object = object.object;
 	}
 
-	if (object.type !== 'Identifier' || !is_store_name(object.name)) {
+	if (object.type !== 'Identifier') {
 		return null;
 	}
 
-	const name = object.name.slice(1);
+	if (is_store_name(object.name)) {
+		const name = object.name.slice(1);
 
-	if (!context.state.scope.get(name)) {
-		return null;
+		if (!context.state.scope.get(name)) {
+			return null;
+		}
+
+		if (object === left) {
+			let value = /** @type {Expression} */ (
+				context.visit(build_assignment_value(operator, left, right))
+			);
+
+			return b.call('$.store_set', b.id(name), value);
+		}
+
+		return b.call(
+			'$.store_mutate',
+			b.assignment('??=', b.id('$$store_subs'), b.object([])),
+			b.literal(object.name),
+			b.id(name),
+			b.assignment(
+				operator,
+				/** @type {Pattern} */ (context.visit(left)),
+				/** @type {Expression} */ (context.visit(right))
+			)
+		);
 	}
 
-	if (object === left) {
+	const binding = context.state.scope.get(object.name);
+
+	// TODO 6.0 this won't work perfectly: once a derived is written to, it will
+	// no longer recompute. It might be better to disallow writing to deriveds
+	// on the server, to prevent this bug occurring
+	if (binding?.kind === 'derived' && object === left) {
 		let value = /** @type {Expression} */ (
 			context.visit(build_assignment_value(operator, left, right))
 		);
 
-		return b.call('$.store_set', b.id(name), value);
+		return b.call(binding.node, value);
 	}
 
-	return b.call(
-		'$.store_mutate',
-		b.assignment('??=', b.id('$$store_subs'), b.object([])),
-		b.literal(object.name),
-		b.id(name),
-		b.assignment(
-			operator,
-			/** @type {Pattern} */ (context.visit(left)),
-			/** @type {Expression} */ (context.visit(right))
-		)
-	);
+	return null;
 }
 
 /**
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/Component.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/Component.js
index 503b380c50..8e7d7bcdbf 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/Component.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/Component.js
@@ -1,3 +1,4 @@
+/** @import { Expression } from 'estree' */
 /** @import { AST } from '#compiler' */
 /** @import { ComponentContext } from '../types.js' */
 import * as b from '#compiler/builders';
@@ -8,5 +9,5 @@ import { build_inline_component } from './shared/component.js';
  * @param {ComponentContext} context
  */
 export function Component(node, context) {
-	build_inline_component(node, b.id(node.name), context);
+	build_inline_component(node, /** @type {Expression} */ (context.visit(b.id(node.name))), context);
 }
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/Identifier.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/Identifier.js
index fa887650b3..460a3411c2 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/Identifier.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/Identifier.js
@@ -14,6 +14,11 @@ export function Identifier(node, context) {
 			return b.id('$$sanitized_props');
 		}
 
+		if (node.name.startsWith('$$derived_array')) {
+			// terrible hack, but easier than adding new stuff to `context.state` for now
+			return b.call(node);
+		}
+
 		return build_getter(node, context.state);
 	}
 }
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/SvelteBoundary.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/SvelteBoundary.js
index 8a30e765c2..47a07a1312 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/SvelteBoundary.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/SvelteBoundary.js
@@ -15,7 +15,17 @@ import {
  * @param {ComponentContext} context
  */
 export function SvelteBoundary(node, context) {
-	// if this has a `pending` snippet, render it
+	// Extract the `failed` snippet/attribute
+	const failed_snippet = /** @type {AST.SnippetBlock | undefined} */ (
+		node.fragment.nodes.find(
+			(node) => node.type === 'SnippetBlock' && node.expression.name === 'failed'
+		)
+	);
+	const failed_attribute = /** @type {AST.Attribute} */ (
+		node.attributes.find((node) => node.type === 'Attribute' && node.name === 'failed')
+	);
+
+	// Extract the `pending` snippet/attribute
 	const pending_attribute = /** @type {AST.Attribute} */ (
 		node.attributes.find((node) => node.type === 'Attribute' && node.name === 'pending')
 	);
@@ -24,48 +34,106 @@ export function SvelteBoundary(node, context) {
 		typeof pending_attribute.value === 'object' &&
 		!Array.isArray(pending_attribute.value) &&
 		!context.state.scope.evaluate(pending_attribute.value.expression).is_defined;
-
-	const pending_snippet = /** @type {AST.SnippetBlock} */ (
+	const pending_snippet = /** @type {AST.SnippetBlock | undefined} */ (
 		node.fragment.nodes.find(
 			(node) => node.type === 'SnippetBlock' && node.expression.name === 'pending'
 		)
 	);
 
+	const children_nodes = node.fragment.nodes.filter(
+		(child) =>
+			!(child.type === 'SnippetBlock' && ['failed', 'pending'].includes(child.expression.name))
+	);
+
+	const children_fragment = { ...node.fragment, nodes: children_nodes };
+	const children_block = /** @type {BlockStatement} */ (
+		context.visit(children_fragment, {
+			...context.state,
+			scope: context.state.scopes.get(node.fragment) ?? context.state.scope
+		})
+	);
+
+	/** @type {BlockStatement} */
+	let children_body;
+
 	if (pending_attribute || pending_snippet) {
 		if (pending_attribute && is_pending_attr_nullish && !pending_snippet) {
-			const callee = build_attribute_value(
-				pending_attribute.value,
-				context,
-				(expression) => expression,
-				false,
-				true
-			);
-			const pending = b.call(callee, b.id('$$renderer'));
-			const block = /** @type {BlockStatement} */ (context.visit(node.fragment));
-			context.state.template.push(
+			const { callee, pending_block } = build_pending_attribute_block(pending_attribute, context);
+
+			children_body = b.block([
 				b.if(
 					callee,
-					b.block(build_template([block_open_else, b.stmt(pending), block_close])),
-					b.block(build_template([block_open, block, block_close]))
+					pending_block,
+					b.block(build_template([block_open, children_block, block_close]))
 				)
-			);
+			]);
 		} else {
-			const pending = pending_attribute
-				? b.call(
-						build_attribute_value(
-							pending_attribute.value,
-							context,
-							(expression) => expression,
-							false,
-							true
-						),
-						b.id('$$renderer')
-					)
-				: /** @type {BlockStatement} */ (context.visit(pending_snippet.body));
-			context.state.template.push(block_open_else, pending, block_close);
+			children_body = pending_attribute
+				? build_pending_attribute_block(pending_attribute, context).pending_block
+				: build_pending_snippet_block(/** @type {AST.SnippetBlock} */ (pending_snippet), context);
 		}
 	} else {
-		const block = /** @type {BlockStatement} */ (context.visit(node.fragment));
-		context.state.template.push(block_open, block, block_close);
+		children_body = b.block(build_template([block_open, children_block, block_close]));
+	}
+
+	// When there's no `failed` snippet/attribute, skip the boundary wrapper entirely
+	// (saves bytes / more performant at runtime)
+	if (!failed_snippet && !failed_attribute) {
+		context.state.template.push(...children_body.body);
+		return;
+	}
+
+	const props = b.object([]);
+	if (failed_attribute && !failed_snippet) {
+		const failed_callee = build_attribute_value(
+			failed_attribute.value,
+			context,
+			(expression) => expression,
+			false,
+			true
+		);
+
+		props.properties.push(b.init('failed', failed_callee));
+	} else if (failed_snippet) {
+		context.visit(failed_snippet, context.state);
+		props.properties.push(b.init('failed', failed_snippet.expression));
 	}
+
+	context.state.template.push(
+		b.stmt(b.call('$$renderer.boundary', props, b.arrow([b.id('$$renderer')], children_body)))
+	);
+}
+
+/**
+ * @param {AST.Attribute} attribute
+ * @param {ComponentContext} context
+ */
+function build_pending_attribute_block(attribute, context) {
+	const callee = build_attribute_value(
+		attribute.value,
+		context,
+		(expression) => expression,
+		false,
+		true
+	);
+	const pending = b.call(callee, b.id('$$renderer'));
+
+	return {
+		callee,
+		pending_block: b.block(build_template([block_open_else, b.stmt(pending), block_close]))
+	};
+}
+
+/**
+ * @param {AST.SnippetBlock} snippet
+ * @param {ComponentContext} context
+ */
+function build_pending_snippet_block(snippet, context) {
+	return b.block(
+		build_template([
+			block_open_else,
+			/** @type {BlockStatement} */ (context.visit(snippet.body)),
+			block_close
+		])
+	);
 }
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/UpdateExpression.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/UpdateExpression.js
index 8a2f874e22..7438ffddce 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/UpdateExpression.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/UpdateExpression.js
@@ -9,17 +9,26 @@ import * as b from '#compiler/builders';
 export function UpdateExpression(node, context) {
 	const argument = node.argument;
 
-	if (
-		argument.type === 'Identifier' &&
-		context.state.scope.get(argument.name)?.kind === 'store_sub'
-	) {
-		return b.call(
-			node.prefix ? '$.update_store_pre' : '$.update_store',
-			b.assignment('??=', b.id('$$store_subs'), b.object([])),
-			b.literal(argument.name),
-			b.id(argument.name.slice(1)),
-			node.operator === '--' && b.literal(-1)
-		);
+	if (argument.type === 'Identifier') {
+		const binding = context.state.scope.get(argument.name);
+
+		if (binding?.kind === 'store_sub') {
+			return b.call(
+				node.prefix ? '$.update_store_pre' : '$.update_store',
+				b.assignment('??=', b.id('$$store_subs'), b.object([])),
+				b.literal(argument.name),
+				b.id(argument.name.slice(1)),
+				node.operator === '--' && b.literal(-1)
+			);
+		}
+
+		if (binding?.kind === 'derived') {
+			return b.call(
+				node.prefix ? '$.update_derived_pre' : '$.update_derived',
+				binding.node,
+				node.operator === '--' && b.literal(-1)
+			);
+		}
 	}
 
 	return context.next();
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/VariableDeclaration.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/VariableDeclaration.js
index 58fde5964f..2c7b14afa5 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/VariableDeclaration.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/VariableDeclaration.js
@@ -84,10 +84,52 @@ export function VariableDeclaration(node, context) {
 			const args = /** @type {CallExpression} */ (init).arguments;
 			const value = args.length > 0 ? /** @type {Expression} */ (context.visit(args[0])) : b.void0;
 
-			if (rune === '$derived.by') {
-				declarations.push(
-					b.declarator(/** @type {Pattern} */ (context.visit(declarator.id)), b.call(value))
-				);
+			if (rune === '$derived' || rune === '$derived.by') {
+				const is_async =
+					rune === '$derived' &&
+					context.state.analysis.async_deriveds.has(
+						/** @type {CallExpression} */ (declarator.init)
+					);
+
+				let init = is_async
+					? b.await(b.call('$.async_derived', b.thunk(value, true)))
+					: b.call('$.derived', rune === '$derived' ? b.thunk(value) : value);
+
+				if (declarator.id.type === 'Identifier') {
+					declarations.push(
+						b.declarator(/** @type {Pattern} */ (context.visit(declarator.id)), init)
+					);
+				} else {
+					const call = /** @type {CallExpression} */ (declarator.init);
+
+					let rhs = value;
+
+					if (rune !== '$derived' || call.arguments[0].type !== 'Identifier') {
+						const id = b.id(context.state.scope.generate('$$d'));
+
+						rhs = b.call(id);
+						declarations.push(b.declarator(id, init));
+					}
+
+					const { inserts, paths } = extract_paths(declarator.id, rhs);
+
+					for (const { id, value } of inserts) {
+						id.name = context.state.scope.generate('$$derived_array');
+
+						const expression = /** @type {Expression} */ (context.visit(b.thunk(value)));
+						const call = b.call('$.derived', expression);
+
+						declarations.push(b.declarator(id, call));
+					}
+
+					for (const path of paths) {
+						const expression = /** @type {Expression} */ (context.visit(path.expression));
+						const call = b.call('$.derived', b.thunk(expression));
+
+						declarations.push(b.declarator(path.node, call));
+					}
+				}
+
 				continue;
 			}
 
@@ -96,13 +138,6 @@ export function VariableDeclaration(node, context) {
 				continue;
 			}
 
-			if (rune === '$derived') {
-				declarations.push(
-					b.declarator(/** @type {Pattern} */ (context.visit(declarator.id)), value)
-				);
-				continue;
-			}
-
 			declarations.push(...create_state_declarators(declarator, context.state.scope, value));
 		}
 	} else {
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/component.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/component.js
index 6a2c6eb0be..b0e086b7ad 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/component.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/component.js
@@ -1,7 +1,14 @@
 /** @import { BlockStatement, Expression, Pattern, Property, SequenceExpression, Statement } from 'estree' */
 /** @import { AST } from '#compiler' */
 /** @import { ComponentContext } from '../../types.js' */
-import { empty_comment, build_attribute_value, PromiseOptimiser } from './utils.js';
+import {
+	empty_comment,
+	build_attribute_value,
+	PromiseOptimiser,
+	block_open_else,
+	block_open,
+	block_close
+} from './utils.js';
 import * as b from '#compiler/builders';
 import { is_element_node } from '../../../../nodes.js';
 import { dev } from '../../../../../state.js';
@@ -300,9 +307,22 @@ export function build_inline_component(node, expression, context) {
 		node.type === 'SvelteComponent' || (node.type === 'Component' && node.metadata.dynamic);
 
 	/** @type {Statement} */
-	let statement = b.stmt(
-		(dynamic ? b.maybe_call : b.call)(expression, b.id('$$renderer'), props_expression)
-	);
+	let statement = b.stmt(b.call(expression, b.id('$$renderer'), props_expression));
+
+	if (dynamic) {
+		statement = b.if(
+			expression,
+			b.block([
+				b.stmt(b.call('$$renderer.push', block_open)),
+				statement,
+				b.stmt(b.call('$$renderer.push', block_close))
+			]),
+			b.block([
+				b.stmt(b.call('$$renderer.push', block_open_else)),
+				b.stmt(b.call('$$renderer.push', block_close))
+			])
+		);
+	}
 
 	if (snippet_declarations.length > 0) {
 		statement = b.block([...snippet_declarations, statement]);
@@ -326,16 +346,14 @@ export function build_inline_component(node, expression, context) {
 		optimiser.check_blockers(node.metadata.expression);
 	}
 
-	context.state.template.push(
-		...optimiser.render_block([
-			dynamic && custom_css_props.length === 0
-				? b.stmt(b.call('$$renderer.push', empty_comment))
-				: b.empty,
-			statement
-		])
-	);
+	context.state.template.push(...optimiser.render_block([statement]));
 
-	if (!optimiser.is_async() && !context.state.is_standalone && custom_css_props.length === 0) {
+	if (
+		!dynamic &&
+		!optimiser.is_async() &&
+		!context.state.is_standalone &&
+		custom_css_props.length === 0
+	) {
 		context.state.template.push(empty_comment);
 	}
 }
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/element.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/element.js
index ac02a6b918..9c37b2fffe 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/element.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/element.js
@@ -123,9 +123,13 @@ export function build_element_attributes(node, context, transform) {
 
 			expression = transform(expression, attribute.metadata.expression);
 
-			if (is_content_editable_binding(attribute.name)) {
+			if (attribute.name === 'innerHTML') {
+				// innerHTML is the only binding we don't escape
 				content = expression;
-			} else if (attribute.name === 'value' && node.name === 'textarea') {
+			} else if (
+				is_content_editable_binding(attribute.name) ||
+				(attribute.name === 'value' && node.name === 'textarea')
+			) {
 				content = b.call('$.escape', expression);
 			} else if (attribute.name === 'group' && attribute.expression.type !== 'SequenceExpression') {
 				const value_attribute = /** @type {AST.Attribute | undefined} */ (
diff --git a/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/utils.js b/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/utils.js
index 1af283791c..a87642bc4c 100644
--- a/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/utils.js
+++ b/packages/svelte/src/compiler/phases/3-transform/server/visitors/shared/utils.js
@@ -274,6 +274,10 @@ export function build_getter(node, state) {
 		);
 	}
 
+	if (binding.kind === 'derived') {
+		return (binding.declaration_kind === 'var' ? b.maybe_call : b.call)(binding.node);
+	}
+
 	return node;
 }
 
diff --git a/packages/svelte/src/compiler/phases/3-transform/shared/assignments.js b/packages/svelte/src/compiler/phases/3-transform/shared/assignments.js
index 0853757775..4678d88ec5 100644
--- a/packages/svelte/src/compiler/phases/3-transform/shared/assignments.js
+++ b/packages/svelte/src/compiler/phases/3-transform/shared/assignments.js
@@ -3,7 +3,6 @@
 /** @import { Context as ServerContext } from '../server/types.js' */
 import { extract_paths, is_expression_async } from '../../../utils/ast.js';
 import * as b from '#compiler/builders';
-import { get_value } from '../client/visitors/shared/declarations.js';
 
 /**
  * @template {ClientContext | ServerContext} Context
diff --git a/packages/svelte/src/compiler/phases/scope.js b/packages/svelte/src/compiler/phases/scope.js
index a320718f58..9d563375d7 100644
--- a/packages/svelte/src/compiler/phases/scope.js
+++ b/packages/svelte/src/compiler/phases/scope.js
@@ -1098,7 +1098,7 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 		},
 
 		FunctionExpression(node, { state, next }) {
-			const scope = state.scope.child();
+			const scope = state.scope.child(true);
 			scopes.set(node, scope);
 
 			if (node.id) scope.declare(node.id, 'normal', 'function');
@@ -1110,7 +1110,7 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 		FunctionDeclaration(node, { state, next }) {
 			if (node.id) state.scope.declare(node.id, 'normal', 'function', node);
 
-			const scope = state.scope.child();
+			const scope = state.scope.child(true);
 			scopes.set(node, scope);
 
 			add_params(scope, node.params);
@@ -1118,7 +1118,7 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 		},
 
 		ArrowFunctionExpression(node, { state, next }) {
-			const scope = state.scope.child();
+			const scope = state.scope.child(true);
 			scopes.set(node, scope);
 
 			add_params(scope, node.params);
@@ -1136,8 +1136,11 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 				parent?.type === 'FunctionExpression' ||
 				parent?.type === 'ArrowFunctionExpression'
 			) {
-				// We already created a new scope for the function
-				context.next();
+				// The scopes created for the function nodes above handle the function identifier and
+				// parameters, but the block statement itself holds the non-porous function scope
+				const scope = context.state.scope.child();
+				scopes.set(node, scope);
+				context.next({ scope });
 			} else {
 				create_block_scope(node, context);
 			}
diff --git a/packages/svelte/src/compiler/print/index.js b/packages/svelte/src/compiler/print/index.js
index 5543b6b581..160aeb4345 100644
--- a/packages/svelte/src/compiler/print/index.js
+++ b/packages/svelte/src/compiler/print/index.js
@@ -18,15 +18,17 @@ const LINE_BREAK_THRESHOLD = 50;
  * @param {import('./types.js').Options | undefined} options
  */
 export function print(ast, options = undefined) {
+	const comments = (ast.type === 'Root' && ast.comments) || [];
+
 	return esrap.print(
 		ast,
 		/** @type {Visitors<AST.SvelteNode>} */ ({
 			...ts({
-				comments: ast.type === 'Root' ? ast.comments : [],
+				comments,
 				getLeadingComments: options?.getLeadingComments,
 				getTrailingComments: options?.getTrailingComments
 			}),
-			...svelte_visitors,
+			...svelte_visitors(comments),
 			...css_visitors
 		})
 	);
@@ -57,35 +59,72 @@ function block(context, node, allow_inline = false) {
 }
 
 /**
+ * @param {AST.BaseNode} node
  * @param {AST.BaseElement['attributes']} attributes
  * @param {Context} context
+ * @param {AST.JSComment[]} comments
  * @returns {boolean} true if attributes were formatted on multiple lines
  */
-function attributes(attributes, context) {
+function attributes(node, attributes, context, comments) {
 	if (attributes.length === 0) {
 		return false;
 	}
 
-	// Measure total width of all attributes when rendered inline
-	const child_context = context.new();
+	let length = -1;
 
-	for (const attribute of attributes) {
-		child_context.write(' ');
-		child_context.visit(attribute);
+	let comment_index = comments.findIndex((comment) => comment.start > node.start);
+
+	if (comment_index === -1) {
+		comment_index = comments.length;
 	}
 
-	const multiline = child_context.measure() > LINE_BREAK_THRESHOLD;
+	const separator = context.new();
+
+	const children = attributes.map((attribute) => {
+		const child_context = context.new();
+
+		while (comment_index < comments.length) {
+			const comment = comments[comment_index];
+
+			if (comment.start < attribute.start) {
+				if (comment.type === 'Line') {
+					child_context.write('//' + comment.value);
+					child_context.newline();
+				} else {
+					child_context.write('/*' + comment.value + '*/'); // TODO match indentation?
+					child_context.append(separator);
+				}
+
+				comment_index += 1;
+			} else {
+				break;
+			}
+		}
+
+		child_context.visit(attribute);
+
+		length += child_context.measure() + 1;
+
+		return child_context;
+	});
+
+	let multiline = context.multiline || length > LINE_BREAK_THRESHOLD;
 
 	if (multiline) {
+		separator.newline();
 		context.indent();
-		for (const attribute of attributes) {
+		for (const child of children) {
 			context.newline();
-			context.visit(attribute);
+			context.append(child);
 		}
 		context.dedent();
 		context.newline();
 	} else {
-		context.append(child_context);
+		separator.write(' ');
+		for (const child of children) {
+			context.write(' ');
+			context.append(child);
+		}
 	}
 
 	return multiline;
@@ -94,8 +133,9 @@ function attributes(attributes, context) {
 /**
  * @param {AST.BaseElement} node
  * @param {Context} context
+ * @param {AST.JSComment[]} comments
  */
-function base_element(node, context) {
+function base_element(node, context, comments) {
 	const child_context = context.new();
 
 	child_context.write('<' + node.name);
@@ -111,7 +151,7 @@ function base_element(node, context) {
 		child_context.write('}');
 	}
 
-	const multiline_attributes = attributes(node.attributes, child_context);
+	const multiline_attributes = attributes(node, node.attributes, child_context, comments);
 	const is_doctype_node = node.name.toLowerCase() === '!doctype';
 	const is_self_closing =
 		is_void(node.name) || (node.type === 'Component' && node.fragment.nodes.length === 0);
@@ -284,8 +324,11 @@ const css_visitors = {
 	}
 };
 
-/** @type {Visitors<AST.SvelteNode>} */
-const svelte_visitors = {
+/**
+ * @param {AST.JSComment[]} comments
+ * @returns {Visitors<AST.SvelteNode>}
+ */
+const svelte_visitors = (comments) => ({
 	Root(node, context) {
 		if (node.options) {
 			context.write('<svelte:options');
@@ -315,7 +358,7 @@ const svelte_visitors = {
 
 	Script(node, context) {
 		context.write('<script');
-		attributes(node.attributes, context);
+		attributes(node, node.attributes, context, comments);
 		context.write('>');
 		block(context, node.content);
 		context.write('</script>');
@@ -545,7 +588,7 @@ const svelte_visitors = {
 	},
 
 	Component(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	ConstTag(node, context) {
@@ -681,7 +724,7 @@ const svelte_visitors = {
 	},
 
 	RegularElement(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	RenderTag(node, context) {
@@ -691,7 +734,7 @@ const svelte_visitors = {
 	},
 
 	SlotElement(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	SnippetBlock(node, context) {
@@ -747,7 +790,7 @@ const svelte_visitors = {
 
 	StyleSheet(node, context) {
 		context.write('<style');
-		attributes(node.attributes, context);
+		attributes(node, node.attributes, context, comments);
 		context.write('>');
 
 		if (node.children.length > 0) {
@@ -774,7 +817,7 @@ const svelte_visitors = {
 	},
 
 	SvelteBoundary(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	SvelteComponent(node, context) {
@@ -783,7 +826,7 @@ const svelte_visitors = {
 		context.write(' this={');
 		context.visit(node.expression);
 		context.write('}');
-		attributes(node.attributes, context);
+		attributes(node, node.attributes, context, comments);
 		if (node.fragment && node.fragment.nodes.length > 0) {
 			context.write('>');
 			block(context, node.fragment, true);
@@ -794,7 +837,7 @@ const svelte_visitors = {
 	},
 
 	SvelteDocument(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	SvelteElement(node, context) {
@@ -803,7 +846,7 @@ const svelte_visitors = {
 		context.write('this={');
 		context.visit(node.tag);
 		context.write('}');
-		attributes(node.attributes, context);
+		attributes(node, node.attributes, context, comments);
 
 		if (node.fragment && node.fragment.nodes.length > 0) {
 			context.write('>');
@@ -815,19 +858,19 @@ const svelte_visitors = {
 	},
 
 	SvelteFragment(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	SvelteHead(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	SvelteSelf(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	SvelteWindow(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	Text(node, context) {
@@ -835,7 +878,7 @@ const svelte_visitors = {
 	},
 
 	TitleElement(node, context) {
-		base_element(node, context);
+		base_element(node, context, comments);
 	},
 
 	TransitionDirective(node, context) {
@@ -865,4 +908,4 @@ const svelte_visitors = {
 			context.write('}');
 		}
 	}
-};
+});
diff --git a/packages/svelte/src/constants.js b/packages/svelte/src/constants.js
index 63324c860f..a3a109b943 100644
--- a/packages/svelte/src/constants.js
+++ b/packages/svelte/src/constants.js
@@ -23,6 +23,8 @@ export const TEMPLATE_USE_MATHML = 1 << 3;
 export const HYDRATION_START = '[';
 /** used to indicate that an `{:else}...` block was rendered */
 export const HYDRATION_START_ELSE = '[!';
+/** used to indicate that a boundary's `failed` snippet was rendered on the server */
+export const HYDRATION_START_FAILED = '[?';
 export const HYDRATION_END = ']';
 export const HYDRATION_ERROR = {};
 
diff --git a/packages/svelte/src/index.d.ts b/packages/svelte/src/index.d.ts
index a1782f5b61..7823c8e33e 100644
--- a/packages/svelte/src/index.d.ts
+++ b/packages/svelte/src/index.d.ts
@@ -21,6 +21,7 @@ export interface ComponentConstructorOptions<
 	sync?: boolean;
 	idPrefix?: string;
 	$$inline?: boolean;
+	transformError?: (error: unknown) => unknown;
 }
 
 /**
@@ -338,6 +339,11 @@ export type MountOptions<Props extends Record<string, any> = Record<string, any>
 	 * @default true
 	 */
 	intro?: boolean;
+	/**
+	 * A function that transforms errors caught by error boundaries before they are passed to the `failed` snippet.
+	 * Defaults to the identity function.
+	 */
+	transformError?: (error: unknown) => unknown | Promise<unknown>;
 } & ({} extends Props
 	? {
 			/**
diff --git a/packages/svelte/src/internal/client/dom/blocks/await.js b/packages/svelte/src/internal/client/dom/blocks/await.js
index 87d64df23e..09a3ec5ca4 100644
--- a/packages/svelte/src/internal/client/dom/blocks/await.js
+++ b/packages/svelte/src/internal/client/dom/blocks/await.js
@@ -12,7 +12,7 @@ import {
 import { queue_micro_task } from '../task.js';
 import { HYDRATION_START_ELSE, UNINITIALIZED } from '../../../../constants.js';
 import { is_runes } from '../../context.js';
-import { Batch, flushSync, is_flushing_sync } from '../../reactivity/batch.js';
+import { Batch, current_batch, flushSync, is_flushing_sync } from '../../reactivity/batch.js';
 import { BranchManager } from './branches.js';
 import { capture, unset_context } from '../../reactivity/async.js';
 
@@ -84,7 +84,7 @@ export function await_block(node, get_input, pending_fn, then_fn, catch_fn) {
 				try {
 					fn();
 				} finally {
-					unset_context();
+					unset_context(false);
 
 					// without this, the DOM does not update until two ticks after the promise
 					// resolves, which is unexpected behaviour (and somewhat irksome to test)
@@ -102,7 +102,7 @@ export function await_block(node, get_input, pending_fn, then_fn, catch_fn) {
 				(e) => {
 					resolve(() => {
 						internal_set(error, e);
-						branches.ensure(THEN, catch_fn && ((target) => catch_fn(target, error)));
+						branches.ensure(CATCH, catch_fn && ((target) => catch_fn(target, error)));
 
 						if (!catch_fn) {
 							// Rethrow the error if no catch block exists
diff --git a/packages/svelte/src/internal/client/dom/blocks/boundary.js b/packages/svelte/src/internal/client/dom/blocks/boundary.js
index 048b5072d2..641b7953ee 100644
--- a/packages/svelte/src/internal/client/dom/blocks/boundary.js
+++ b/packages/svelte/src/internal/client/dom/blocks/boundary.js
@@ -1,15 +1,18 @@
 /** @import { Effect, Source, TemplateNode, } from '#client' */
 import {
 	BOUNDARY_EFFECT,
+<<<<<<< HEAD
 	BRANCH_EFFECT,
 	CLEAN,
 	COMMENT_NODE,
+=======
+>>>>>>> main
 	DIRTY,
 	EFFECT_PRESERVED,
 	EFFECT_TRANSPARENT,
 	MAYBE_DIRTY
 } from '#client/constants';
-import { HYDRATION_START_ELSE } from '../../../../constants.js';
+import { HYDRATION_START_ELSE, HYDRATION_START_FAILED } from '../../../../constants.js';
 import { component_context, set_component_context } from '../../context.js';
 import { handle_error, invoke_error_boundary } from '../../error-handling.js';
 import {
@@ -60,10 +63,11 @@ var flags = EFFECT_TRANSPARENT | EFFECT_PRESERVED;
  * @param {TemplateNode} node
  * @param {BoundaryProps} props
  * @param {((anchor: Node) => void)} children
+ * @param {((error: unknown) => unknown) | undefined} [transform_error]
  * @returns {void}
  */
-export function boundary(node, props, children) {
-	new Boundary(node, props, children);
+export function boundary(node, props, children, transform_error) {
+	new Boundary(node, props, children, transform_error);
 }
 
 export class Boundary {
@@ -72,6 +76,13 @@ export class Boundary {
 
 	is_pending = false;
 
+	/**
+	 * API-level transformError transform function. Transforms errors before they reach the `failed` snippet.
+	 * Inherited from parent boundary, or defaults to identity.
+	 * @type {(error: unknown) => unknown}
+	 */
+	transform_error;
+
 	/** @type {TemplateNode} */
 	#anchor;
 
@@ -134,8 +145,9 @@ export class Boundary {
 	 * @param {TemplateNode} node
 	 * @param {BoundaryProps} props
 	 * @param {((anchor: Node) => void)} children
+	 * @param {((error: unknown) => unknown) | undefined} [transform_error]
 	 */
-	constructor(node, props, children) {
+	constructor(node, props, children, transform_error) {
 		this.#anchor = node;
 		this.#props = props;
 
@@ -150,12 +162,23 @@ export class Boundary {
 
 		this.parent = /** @type {Effect} */ (active_effect).b;
 
+		// Inherit transform_error from parent boundary, or use the provided one, or default to identity
+		this.transform_error = transform_error ?? this.parent?.transform_error ?? ((e) => e);
+
 		this.#effect = block(() => {
 			if (hydrating) {
 				const comment = /** @type {Comment} */ (this.#hydrate_open);
 				hydrate_next();
 
-				if (comment.data === HYDRATION_START_ELSE) {
+				const server_rendered_pending = comment.data === HYDRATION_START_ELSE;
+				const server_rendered_failed = comment.data.startsWith(HYDRATION_START_FAILED);
+
+				if (server_rendered_failed) {
+					// Server rendered the failed snippet - hydrate it.
+					// The serialized error is embedded in the comment: <!--[?<json>-->
+					const serialized_error = JSON.parse(comment.data.slice(HYDRATION_START_FAILED.length));
+					this.#hydrate_failed_content(serialized_error);
+				} else if (server_rendered_pending) {
 					this.#hydrate_pending_content();
 				} else {
 					this.#hydrate_resolved_content();
@@ -178,6 +201,22 @@ export class Boundary {
 		}
 	}
 
+	/**
+	 * @param {unknown} error The deserialized error from the server's hydration comment
+	 */
+	#hydrate_failed_content(error) {
+		const failed = this.#props.failed;
+		if (!failed) return;
+
+		this.#failed_effect = branch(() => {
+			failed(
+				this.#anchor,
+				() => error,
+				() => () => {}
+			);
+		});
+	}
+
 	#hydrate_pending_content() {
 		const pending = this.#props.pending;
 		if (!pending) return;
@@ -422,10 +461,11 @@ export class Boundary {
 			});
 		};
 
-		queue_micro_task(() => {
+		/** @param {unknown} transformed_error */
+		const handle_error_result = (transformed_error) => {
 			try {
 				calling_on_error = true;
-				onerror?.(error, reset);
+				onerror?.(transformed_error, reset);
 				calling_on_error = false;
 			} catch (error) {
 				invoke_error_boundary(error, this.#effect && this.#effect.parent);
@@ -446,7 +486,7 @@ export class Boundary {
 
 							failed(
 								this.#anchor,
-								() => error,
+								() => transformed_error,
 								() => reset
 							);
 						});
@@ -456,6 +496,34 @@ export class Boundary {
 					}
 				});
 			}
+		};
+
+		queue_micro_task(() => {
+			// Run the error through the API-level transformError transform (e.g. SvelteKit's handleError)
+			/** @type {unknown} */
+			var result;
+			try {
+				result = this.transform_error(error);
+			} catch (e) {
+				invoke_error_boundary(e, this.#effect && this.#effect.parent);
+				return;
+			}
+
+			if (
+				result !== null &&
+				typeof result === 'object' &&
+				typeof (/** @type {any} */ (result).then) === 'function'
+			) {
+				// transformError returned a Promise — wait for it
+				/** @type {any} */ (result).then(
+					handle_error_result,
+					/** @param {unknown} e */
+					(e) => invoke_error_boundary(e, this.#effect && this.#effect.parent)
+				);
+			} else {
+				// Synchronous result — handle immediately
+				handle_error_result(result);
+			}
 		});
 	}
 }
diff --git a/packages/svelte/src/internal/client/dom/blocks/branches.js b/packages/svelte/src/internal/client/dom/blocks/branches.js
index 6b77903574..a8096e0a58 100644
--- a/packages/svelte/src/internal/client/dom/blocks/branches.js
+++ b/packages/svelte/src/internal/client/dom/blocks/branches.js
@@ -68,9 +68,10 @@ export class BranchManager {
 		this.#transition = transition;
 	}
 
-	#commit = () => {
-		var batch = /** @type {Batch} */ (current_batch);
-
+	/**
+	 * @param {Batch} batch
+	 */
+	#commit = (batch) => {
 		// if this batch was made obsolete, bail
 		if (!this.#batches.has(batch)) return;
 
@@ -221,7 +222,7 @@ export class BranchManager {
 				this.anchor = hydrate_node;
 			}
 
-			this.#commit();
+			this.#commit(batch);
 		}
 	}
 }
diff --git a/packages/svelte/src/internal/client/dom/blocks/each.js b/packages/svelte/src/internal/client/dom/blocks/each.js
index 25f7cf91eb..7ae02d073c 100644
--- a/packages/svelte/src/internal/client/dom/blocks/each.js
+++ b/packages/svelte/src/internal/client/dom/blocks/each.js
@@ -250,6 +250,14 @@ export function each(node, flags, get_collection, get_key, render_fn, fallback_f
 			var value = array[index];
 			var key = get_key(value, index);
 
+			if (DEV) {
+				// Check that the key function is idempotent (returns the same value when called twice)
+				var key_again = get_key(value, index);
+				if (key !== key_again) {
+					e.each_key_volatile(String(index), String(key), String(key_again));
+				}
+			}
+
 			var item = first_run ? null : items.get(key);
 
 			if (item) {
diff --git a/packages/svelte/src/internal/client/dom/blocks/html.js b/packages/svelte/src/internal/client/dom/blocks/html.js
index 1d337c1f74..af66a04534 100644
--- a/packages/svelte/src/internal/client/dom/blocks/html.js
+++ b/packages/svelte/src/internal/client/dom/blocks/html.js
@@ -1,21 +1,27 @@
 /** @import { Effect, TemplateNode } from '#client' */
-import { FILENAME, HYDRATION_ERROR } from '../../../../constants.js';
+/** @import {} from 'trusted-types' */
+import {
+	FILENAME,
+	HYDRATION_ERROR,
+	NAMESPACE_SVG,
+	NAMESPACE_MATHML
+} from '../../../../constants.js';
 import { remove_effect_dom, template_effect } from '../../reactivity/effects.js';
 import { hydrate_next, hydrate_node, hydrating, set_hydrate_node } from '../hydration.js';
-import { create_fragment_from_html } from '../reconciler.js';
+
 import { assign_nodes } from '../template.js';
 import * as w from '../../warnings.js';
 import { hash, sanitize_location } from '../../../../utils.js';
 import { DEV } from 'esm-env';
 import { dev_current_component_function } from '../../context.js';
-import { get_first_child, get_next_sibling } from '../operations.js';
+import { create_element, get_first_child, get_next_sibling } from '../operations.js';
 import { active_effect } from '../../runtime.js';
 import { COMMENT_NODE } from '#client/constants';
 
 /**
  * @param {Element} element
  * @param {string | null} server_hash
- * @param {string} value
+ * @param {string | TrustedHTML} value
  */
 function check_hash(element, server_hash, value) {
 	if (!server_hash || server_hash === hash(String(value ?? ''))) return;
@@ -35,7 +41,7 @@ function check_hash(element, server_hash, value) {
 
 /**
  * @param {Element | Text | Comment} node
- * @param {() => string} get_value
+ * @param {() => string | TrustedHTML} get_value
  * @param {boolean} [svg]
  * @param {boolean} [mathml]
  * @param {boolean} [skip_warning]
@@ -44,6 +50,7 @@ function check_hash(element, server_hash, value) {
 export function html(node, get_value, svg = false, mathml = false, skip_warning = false) {
 	var anchor = node;
 
+	/** @type {string | TrustedHTML} */
 	var value = '';
 
 	template_effect(() => {
@@ -92,18 +99,18 @@ export function html(node, get_value, svg = false, mathml = false, skip_warning
 			return;
 		}
 
-		var html = value + '';
-		if (svg) html = `<svg>${html}</svg>`;
-		else if (mathml) html = `<math>${html}</math>`;
-
 		// Don't use create_fragment_with_script_from_html here because that would mean script tags are executed.
 		// @html is basically `.innerHTML = ...` and that doesn't execute scripts either due to security reasons.
-		/** @type {DocumentFragment | Element} */
-		var node = create_fragment_from_html(html);
+		// Use a <template>, <svg>, or <math> wrapper depending on context. If value is a TrustedHTML object,
+		// it will be assigned directly to innerHTML without coercion — this allows {@html policy.createHTML(...)} to work.
+		var ns = svg ? NAMESPACE_SVG : mathml ? NAMESPACE_MATHML : undefined;
+		var wrapper = /** @type {HTMLTemplateElement | SVGElement | MathMLElement} */ (
+			create_element(svg ? 'svg' : mathml ? 'math' : 'template', ns)
+		);
+		wrapper.innerHTML = /** @type {any} */ (value);
 
-		if (svg || mathml) {
-			node = /** @type {Element} */ (get_first_child(node));
-		}
+		/** @type {DocumentFragment | Element} */
+		var node = svg || mathml ? wrapper : /** @type {HTMLTemplateElement} */ (wrapper).content;
 
 		assign_nodes(
 			/** @type {TemplateNode} */ (get_first_child(node)),
diff --git a/packages/svelte/src/internal/client/dom/blocks/if.js b/packages/svelte/src/internal/client/dom/blocks/if.js
index f2b1cf80a5..44f5fdd1bc 100644
--- a/packages/svelte/src/internal/client/dom/blocks/if.js
+++ b/packages/svelte/src/internal/client/dom/blocks/if.js
@@ -6,7 +6,8 @@ import {
 	read_hydration_instruction,
 	skip_nodes,
 	set_hydrate_node,
-	set_hydrating
+	set_hydrating,
+	hydrate_node
 } from '../hydration.js';
 import { block } from '../../reactivity/effects.js';
 import { BranchManager } from './branches.js';
@@ -19,7 +20,10 @@ import { HYDRATION_START, HYDRATION_START_ELSE } from '../../../../constants.js'
  * @returns {void}
  */
 export function if_block(node, fn, elseif = false) {
+	/** @type {TemplateNode | undefined} */
+	var marker;
 	if (hydrating) {
+		marker = hydrate_node;
 		hydrate_next();
 	}
 
@@ -32,8 +36,7 @@ export function if_block(node, fn, elseif = false) {
 	 */
 	function update_branch(key, fn) {
 		if (hydrating) {
-			const data = read_hydration_instruction(node);
-
+			var data = read_hydration_instruction(/** @type {TemplateNode} */ (marker));
 			/**
 			 * @type {number | false}
 			 * "[" = branch 0, "[1" = branch 1, "[2" = branch 2, ..., "[!" = else (false)
diff --git a/packages/svelte/src/internal/client/dom/blocks/snippet.js b/packages/svelte/src/internal/client/dom/blocks/snippet.js
index 7da7e5072d..0c4948aca0 100644
--- a/packages/svelte/src/internal/client/dom/blocks/snippet.js
+++ b/packages/svelte/src/internal/client/dom/blocks/snippet.js
@@ -83,7 +83,7 @@ export function createRawSnippet(fn) {
 			hydrate_next();
 		} else {
 			var html = snippet.render().trim();
-			var fragment = create_fragment_from_html(html, true);
+			var fragment = create_fragment_from_html(html);
 			element = /** @type {Element} */ (get_first_child(fragment));
 
 			if (DEV && (get_next_sibling(element) !== null || element.nodeType !== ELEMENT_NODE)) {
diff --git a/packages/svelte/src/internal/client/dom/blocks/svelte-component.js b/packages/svelte/src/internal/client/dom/blocks/svelte-component.js
index 134e57e627..0e9434386c 100644
--- a/packages/svelte/src/internal/client/dom/blocks/svelte-component.js
+++ b/packages/svelte/src/internal/client/dom/blocks/svelte-component.js
@@ -1,8 +1,17 @@
 /** @import { TemplateNode, Dom } from '#client' */
 import { EFFECT_TRANSPARENT } from '#client/constants';
 import { block } from '../../reactivity/effects.js';
-import { hydrate_next, hydrating } from '../hydration.js';
+import {
+	hydrate_next,
+	hydrate_node,
+	hydrating,
+	read_hydration_instruction,
+	set_hydrate_node,
+	set_hydrating,
+	skip_nodes
+} from '../hydration.js';
 import { BranchManager } from './branches.js';
+import { HYDRATION_START, HYDRATION_START_ELSE } from '../../../../constants.js';
 
 /**
  * @template P
@@ -13,7 +22,11 @@ import { BranchManager } from './branches.js';
  * @returns {void}
  */
 export function component(node, get_component, render_fn) {
+	/** @type {TemplateNode | undefined} */
+	var hydration_start_node;
+
 	if (hydrating) {
+		hydration_start_node = hydrate_node;
 		hydrate_next();
 	}
 
@@ -21,6 +34,28 @@ export function component(node, get_component, render_fn) {
 
 	block(() => {
 		var component = get_component() ?? null;
+
+		if (hydrating) {
+			var data = read_hydration_instruction(/** @type {TemplateNode} */ (hydration_start_node));
+
+			var server_had_component = data === HYDRATION_START;
+			var client_has_component = component !== null;
+
+			if (server_had_component !== client_has_component) {
+				// Hydration mismatch: skip the server-rendered nodes and render fresh
+				var anchor = skip_nodes();
+
+				set_hydrate_node(anchor);
+				branches.anchor = anchor;
+
+				set_hydrating(false);
+				branches.ensure(component, component && ((target) => render_fn(target, component)));
+				set_hydrating(true);
+
+				return;
+			}
+		}
+
 		branches.ensure(component, component && ((target) => render_fn(target, component)));
 	}, EFFECT_TRANSPARENT);
 }
diff --git a/packages/svelte/src/internal/client/dom/blocks/svelte-head.js b/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
index 7c7eed24f7..7cab6c3385 100644
--- a/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
+++ b/packages/svelte/src/internal/client/dom/blocks/svelte-head.js
@@ -2,7 +2,7 @@
 import { hydrate_node, hydrating, set_hydrate_node, set_hydrating } from '../hydration.js';
 import { create_text, get_first_child, get_next_sibling } from '../operations.js';
 import { block } from '../../reactivity/effects.js';
-import { COMMENT_NODE, HEAD_EFFECT } from '#client/constants';
+import { COMMENT_NODE, EFFECT_PRESERVED, HEAD_EFFECT } from '#client/constants';
 
 /**
  * @param {string} hash
@@ -49,7 +49,9 @@ export function head(hash, render_fn) {
 	}
 
 	try {
-		block(() => render_fn(anchor), HEAD_EFFECT);
+		// normally a branch is the child of a block and would have the EFFECT_PRESERVED flag,
+		// but since head blocks don't necessarily only have direct branch children we add it on the block itself
+		block(() => render_fn(anchor), HEAD_EFFECT | EFFECT_PRESERVED);
 	} finally {
 		if (was_hydrating) {
 			set_hydrating(true);
diff --git a/packages/svelte/src/internal/client/dom/elements/customizable-select.js b/packages/svelte/src/internal/client/dom/elements/customizable-select.js
index b9f20f63a8..04a3cdd191 100644
--- a/packages/svelte/src/internal/client/dom/elements/customizable-select.js
+++ b/packages/svelte/src/internal/client/dom/elements/customizable-select.js
@@ -1,5 +1,6 @@
 import { hydrating, reset, set_hydrate_node, set_hydrating } from '../hydration.js';
 import { create_comment, create_element } from '../operations.js';
+import { create_trusted_html } from '../reconciler.js';
 import { attach } from './attachments.js';
 
 /** @type {boolean | null} */
@@ -14,7 +15,7 @@ let supported = null;
 function is_supported() {
 	if (supported === null) {
 		var select = create_element('select');
-		select.innerHTML = '<option><span>t</span></option>';
+		select.innerHTML = create_trusted_html('<option><span>t</span></option>');
 		supported = /** @type {Element} */ (select.firstChild)?.firstChild?.nodeType === 1;
 	}
 
diff --git a/packages/svelte/src/internal/client/dom/reconciler.js b/packages/svelte/src/internal/client/dom/reconciler.js
index 0ceebd3337..294cd9c35d 100644
--- a/packages/svelte/src/internal/client/dom/reconciler.js
+++ b/packages/svelte/src/internal/client/dom/reconciler.js
@@ -1,5 +1,3 @@
-/** @import {} from 'trusted-types' */
-
 import { create_element } from './operations.js';
 
 const policy =
@@ -13,17 +11,15 @@ const policy =
 	});
 
 /** @param {string} html */
-function create_trusted_html(html) {
+export function create_trusted_html(html) {
 	return /** @type {string} */ (policy?.createHTML(html) ?? html);
 }
 
 /**
  * @param {string} html
- * @param {boolean} trusted
  */
-export function create_fragment_from_html(html, trusted = false) {
+export function create_fragment_from_html(html) {
 	var elem = create_element('template');
-	html = html.replaceAll('<!>', '<!---->'); // XHTML compliance
-	elem.innerHTML = trusted ? create_trusted_html(html) : html;
+	elem.innerHTML = create_trusted_html(html.replaceAll('<!>', '<!---->')); // XHTML compliance
 	return elem.content;
 }
diff --git a/packages/svelte/src/internal/client/dom/template.js b/packages/svelte/src/internal/client/dom/template.js
index 7e12ff433f..a5d0405d0a 100644
--- a/packages/svelte/src/internal/client/dom/template.js
+++ b/packages/svelte/src/internal/client/dom/template.js
@@ -70,7 +70,7 @@ export function from_html(content, flags) {
 		}
 
 		if (node === undefined) {
-			node = create_fragment_from_html(has_start ? content : '<!>' + content, true);
+			node = create_fragment_from_html(has_start ? content : '<!>' + content);
 			if (!is_fragment) node = /** @type {TemplateNode} */ (get_first_child(node));
 		}
 
@@ -118,7 +118,7 @@ function from_namespace(content, flags, ns = 'svg') {
 		}
 
 		if (!node) {
-			var fragment = /** @type {DocumentFragment} */ (create_fragment_from_html(wrapped, true));
+			var fragment = /** @type {DocumentFragment} */ (create_fragment_from_html(wrapped));
 			var root = /** @type {Element} */ (get_first_child(fragment));
 
 			if (is_fragment) {
diff --git a/packages/svelte/src/internal/client/errors.js b/packages/svelte/src/internal/client/errors.js
index 34f1d85540..d60c2dd280 100644
--- a/packages/svelte/src/internal/client/errors.js
+++ b/packages/svelte/src/internal/client/errors.js
@@ -147,6 +147,25 @@ export function each_key_duplicate(a, b, value) {
 	}
 }
 
+/**
+ * Keyed each block has key that is not idempotent — the key for item at index %index% was `%a%` but is now `%b%`. Keys must be the same each time for a given item
+ * @param {string} index
+ * @param {string} a
+ * @param {string} b
+ * @returns {never}
+ */
+export function each_key_volatile(index, a, b) {
+	if (DEV) {
+		const error = new Error(`each_key_volatile\nKeyed each block has key that is not idempotent — the key for item at index ${index} was \`${a}\` but is now \`${b}\`. Keys must be the same each time for a given item\nhttps://svelte.dev/e/each_key_volatile`);
+
+		error.name = 'Svelte error';
+
+		throw error;
+	} else {
+		throw new Error(`https://svelte.dev/e/each_key_volatile`);
+	}
+}
+
 /**
  * `%rune%` cannot be used inside an effect cleanup function
  * @param {string} rune
diff --git a/packages/svelte/src/internal/client/index.js b/packages/svelte/src/internal/client/index.js
index fedabd6ac1..af8df2e32c 100644
--- a/packages/svelte/src/internal/client/index.js
+++ b/packages/svelte/src/internal/client/index.js
@@ -153,7 +153,6 @@ export {
 	safe_get,
 	tick,
 	untrack,
-	exclude_from_object,
 	deep_read,
 	deep_read_state,
 	active_effect
@@ -171,7 +170,7 @@ export {
 } from './dom/operations.js';
 export { attr, clsx } from '../shared/attributes.js';
 export { snapshot } from '../shared/clone.js';
-export { noop, fallback, to_array } from '../shared/utils.js';
+export { noop, fallback, to_array, exclude_from_object } from '../shared/utils.js';
 export {
 	invalid_default_snippet,
 	validate_dynamic_element_tag,
diff --git a/packages/svelte/src/internal/client/reactivity/async.js b/packages/svelte/src/internal/client/reactivity/async.js
index b3c5248179..f2643e0c34 100644
--- a/packages/svelte/src/internal/client/reactivity/async.js
+++ b/packages/svelte/src/internal/client/reactivity/async.js
@@ -66,7 +66,6 @@ export function flatten(blockers, sync, async, fn) {
 			}
 		}
 
-		batch?.deactivate();
 		unset_context();
 	}
 
@@ -207,10 +206,11 @@ export async function* for_await_track_reactivity_loss(iterable) {
 	}
 }
 
-export function unset_context() {
+export function unset_context(deactivate_batch = true) {
 	set_active_effect(null);
 	set_active_reaction(null);
 	set_component_context(null);
+	if (deactivate_batch) current_batch?.deactivate();
 
 	if (DEV) {
 		set_from_async_derived(null);
@@ -248,6 +248,7 @@ export function run(thunks) {
 
 	promise.finally(() => {
 		blocker.settled = true;
+		unset_context();
 	});
 
 	for (const fn of thunks.slice(1)) {
@@ -271,9 +272,7 @@ export function run(thunks) {
 
 		promise.finally(() => {
 			blocker.settled = true;
-
 			unset_context();
-			current_batch?.deactivate();
 		});
 	}
 
diff --git a/packages/svelte/src/internal/client/reactivity/batch.js b/packages/svelte/src/internal/client/reactivity/batch.js
index 648059f5bf..94aea6776a 100644
--- a/packages/svelte/src/internal/client/reactivity/batch.js
+++ b/packages/svelte/src/internal/client/reactivity/batch.js
@@ -1,6 +1,5 @@
 /** @import { Fork } from 'svelte' */
 /** @import { Derived, Effect, Reaction, Source, Value } from '#client' */
-/** @import { Boundary } from '../dom/blocks/boundary' */
 import {
 	BLOCK_EFFECT,
 	BRANCH_EFFECT,
@@ -14,11 +13,11 @@ import {
 	ROOT_EFFECT,
 	MAYBE_DIRTY,
 	DERIVED,
-	BOUNDARY_EFFECT,
 	EAGER_EFFECT,
 	HEAD_EFFECT,
 	ERROR_VALUE,
-	MANAGED_EFFECT
+	MANAGED_EFFECT,
+	REACTION_RAN
 } from '#client/constants';
 import { async_mode_flag } from '../../flags/index.js';
 import { deferred, define_property, includes } from '../../shared/utils.js';
@@ -70,9 +69,15 @@ let last_scheduled_effect = null;
 let is_flushing = false;
 export let is_flushing_sync = false;
 
-export class Batch {
-	committed = false;
+/**
+ * During traversal, this is an array. Newly created effects are (if not immediately
+ * executed) pushed to this array, rather than going through the scheduling
+ * rigamarole that would cause another turn of the flush loop.
+ * @type {Effect[] | null}
+ */
+export let collected_effects = null;
 
+export class Batch {
 	/**
 	 * The current values of any sources that are updated in this batch
 	 * They keys of this map are identical to `this.#previous`
@@ -90,7 +95,7 @@ export class Batch {
 	/**
 	 * When the batch is committed (and the DOM is updated), we need to remove old branches
 	 * and append new ones by calling the functions added inside (if/each/key/etc) blocks
-	 * @type {Set<() => void>}
+	 * @type {Set<(batch: Batch) => void>}
 	 */
 	#commit_callbacks = new Set();
 
@@ -188,7 +193,7 @@ export class Batch {
 		this.apply();
 
 		/** @type {Effect[]} */
-		var effects = [];
+		var effects = (collected_effects = []);
 
 		/** @type {Effect[]} */
 		var render_effects = [];
@@ -202,6 +207,8 @@ export class Batch {
 			// log_inconsistent_branches(root);
 		}
 
+		collected_effects = null;
+
 		if (this.#is_deferred()) {
 			this.#defer_effects(render_effects);
 			this.#defer_effects(effects);
@@ -210,22 +217,26 @@ export class Batch {
 				reset_branch(e, t);
 			}
 		} else {
+			// If sources are written to, then work needs to happen in a separate batch, else prior sources would be mixed with
+			// newly updated sources, which could lead to infinite loops when effects run over and over again.
+			previous_batch = this;
+			current_batch = null;
+
 			// append/remove branches
-			for (const fn of this.#commit_callbacks) fn();
+			for (const fn of this.#commit_callbacks) fn(this);
 			this.#commit_callbacks.clear();
 
 			if (this.#pending === 0) {
 				this.#commit();
 			}
 
-			// If sources are written to, then work needs to happen in a separate batch, else prior sources would be mixed with
-			// newly updated sources, which could lead to infinite loops when effects run over and over again.
-			previous_batch = this;
-			current_batch = null;
-
 			flush_queued_effects(render_effects);
 			flush_queued_effects(effects);
 
+			// Clear effects. Those that are still needed will be rescheduled through unskipping the skipped branches.
+			this.#dirty_effects.clear();
+			this.#maybe_dirty_effects.clear();
+
 			previous_batch = null;
 
 			this.#deferred?.resolve();
@@ -246,9 +257,6 @@ export class Batch {
 
 		var effect = root.first;
 
-		/** @type {Effect | null} */
-		var pending_boundary = null;
-
 		while (effect !== null) {
 			var flags = effect.f;
 			var is_branch = (flags & (BRANCH_EFFECT | ROOT_EFFECT)) !== 0;
@@ -256,26 +264,9 @@ export class Batch {
 
 			var skip = is_skippable_branch || (flags & INERT) !== 0 || this.#skipped_branches.has(effect);
 
-			// Inside a `<svelte:boundary>` with a pending snippet,
-			// all effects are deferred until the boundary resolves
-			// (except block/async effects, which run immediately)
-			if (
-				async_mode_flag &&
-				pending_boundary === null &&
-				(flags & BOUNDARY_EFFECT) !== 0 &&
-				effect.b?.is_pending
-			) {
-				pending_boundary = effect;
-			}
-
 			if (!skip && effect.fn !== null) {
 				if (is_branch) {
 					effect.f ^= CLEAN;
-				} else if (
-					pending_boundary !== null &&
-					(flags & (EFFECT | RENDER_EFFECT | MANAGED_EFFECT)) !== 0
-				) {
-					/** @type {Boundary} */ (pending_boundary.b).defer_effect(effect);
 				} else if ((flags & EFFECT) !== 0) {
 					effects.push(effect);
 				} else if (async_mode_flag && (flags & (RENDER_EFFECT | MANAGED_EFFECT)) !== 0) {
@@ -294,10 +285,6 @@ export class Batch {
 			}
 
 			while (effect !== null) {
-				if (effect === pending_boundary) {
-					pending_boundary = null;
-				}
-
 				var next = effect.next;
 
 				if (next !== null) {
@@ -352,17 +339,16 @@ export class Batch {
 	}
 
 	flush() {
-		this.activate();
-
 		if (queued_root_effects.length > 0) {
+			this.activate();
 			flush_effects();
+		} else if (this.#pending === 0 && !this.is_fork) {
+			// append/remove branches
+			for (const fn of this.#commit_callbacks) fn(this);
+			this.#commit_callbacks.clear();
 
-			if (current_batch !== null && current_batch !== this) {
-				// this can happen if a new batch was created during `flush_effects()`
-				return;
-			}
-		} else if (this.#pending === 0) {
-			this.process([]); // TODO this feels awkward
+			this.#commit();
+			this.#deferred?.resolve();
 		}
 
 		this.deactivate();
@@ -381,6 +367,7 @@ export class Batch {
 		if (batches.size > 1) {
 			this.previous.clear();
 
+			var previous_batch = current_batch;
 			var previous_batch_values = batch_values;
 			var is_earlier = true;
 
@@ -444,11 +431,11 @@ export class Batch {
 				}
 			}
 
-			current_batch = null;
+			current_batch = previous_batch;
 			batch_values = previous_batch_values;
 		}
 
-		this.committed = true;
+		this.#skipped_branches.clear();
 		batches.delete(this);
 	}
 
@@ -502,7 +489,7 @@ export class Batch {
 		this.flush();
 	}
 
-	/** @param {() => void} fn */
+	/** @param {(batch: Batch) => void} fn */
 	oncommit(fn) {
 		this.#commit_callbacks.add(fn);
 	}
@@ -654,6 +641,7 @@ function flush_effects() {
 
 		is_flushing = false;
 		last_scheduled_effect = null;
+		collected_effects = null;
 
 		if (DEV) {
 			for (const source of /** @type {Set<Source>} */ (source_stacks)) {
@@ -839,6 +827,19 @@ function depends_on(reaction, sources, checked) {
 export function schedule_effect(signal) {
 	var effect = (last_scheduled_effect = signal);
 
+	var boundary = effect.b;
+
+	// defer render effects inside a pending boundary
+	// TODO the `REACTION_RAN` check is only necessary because of legacy `$:` effects AFAICT — we can remove later
+	if (
+		boundary?.is_pending &&
+		(signal.f & (EFFECT | RENDER_EFFECT | MANAGED_EFFECT)) !== 0 &&
+		(signal.f & REACTION_RAN) === 0
+	) {
+		boundary.defer_effect(signal);
+		return;
+	}
+
 	while (effect.parent !== null) {
 		effect = effect.parent;
 		var flags = effect.f;
@@ -846,17 +847,21 @@ export function schedule_effect(signal) {
 		// if the effect is being scheduled because a parent (each/await/etc) block
 		// updated an internal source, or because a branch is being unskipped,
 		// bail out or we'll cause a second flush
-		if (
-			is_flushing &&
-			effect === active_effect &&
-			(flags & BLOCK_EFFECT) !== 0 &&
-			(flags & HEAD_EFFECT) === 0
-		) {
-			return;
+		if (collected_effects !== null && effect === active_effect) {
+			// in sync mode, render effects run during traversal. in an extreme edge case
+			// they can be made dirty after they have already been visited, in which
+			// case we shouldn't bail out
+			if (async_mode_flag || (signal.f & RENDER_EFFECT) === 0) {
+				return;
+			}
 		}
 
 		if ((flags & (ROOT_EFFECT | BRANCH_EFFECT)) !== 0) {
-			if ((flags & CLEAN) === 0) return;
+			if ((flags & CLEAN) === 0) {
+				// branch is already dirty, bail
+				return;
+			}
+
 			effect.f ^= CLEAN;
 		}
 
diff --git a/packages/svelte/src/internal/client/reactivity/deriveds.js b/packages/svelte/src/internal/client/reactivity/deriveds.js
index 80da5528c8..7df7651294 100644
--- a/packages/svelte/src/internal/client/reactivity/deriveds.js
+++ b/packages/svelte/src/internal/client/reactivity/deriveds.js
@@ -133,17 +133,7 @@ export function async_derived(fn, label, location) {
 			// If this code is changed at some point, make sure to still access the then property
 			// of fn() to read any signals it might access, so that we track them as dependencies.
 			// We call `unset_context` to undo any `save` calls that happen inside `fn()`
-			Promise.resolve(fn())
-				.then(d.resolve, d.reject)
-				.then(() => {
-					if (batch === current_batch && batch.committed) {
-						// if the batch was rejected as stale, we need to cleanup
-						// after any `$.save(...)` calls inside `fn()`
-						batch.deactivate();
-					}
-
-					unset_context();
-				});
+			Promise.resolve(fn()).then(d.resolve, d.reject).finally(unset_context);
 		} catch (error) {
 			d.reject(error);
 			unset_context();
diff --git a/packages/svelte/src/internal/client/reactivity/effects.js b/packages/svelte/src/internal/client/reactivity/effects.js
index 157587e218..b670e7ab55 100644
--- a/packages/svelte/src/internal/client/reactivity/effects.js
+++ b/packages/svelte/src/internal/client/reactivity/effects.js
@@ -40,7 +40,7 @@ import { DEV } from 'esm-env';
 import { define_property } from '../../shared/utils.js';
 import { get_next_sibling } from '../dom/operations.js';
 import { component_context, dev_current_component_function, dev_stack } from '../context.js';
-import { Batch, schedule_effect } from './batch.js';
+import { Batch, collected_effects, schedule_effect } from './batch.js';
 import { flatten, increment_pending } from './async.js';
 import { without_reactive_context } from '../dom/elements/bindings/shared.js';
 import { set_signal_status } from './status.js';
@@ -80,10 +80,9 @@ function push_effect(effect, parent_effect) {
 /**
  * @param {number} type
  * @param {null | (() => void | (() => void))} fn
- * @param {boolean} sync
  * @returns {Effect}
  */
-function create_effect(type, fn, sync) {
+function create_effect(type, fn) {
 	var parent = active_effect;
 
 	if (DEV) {
@@ -119,34 +118,39 @@ function create_effect(type, fn, sync) {
 		effect.component_function = dev_current_component_function;
 	}
 
-	if (sync) {
+	/** @type {Effect | null} */
+	var e = effect;
+
+	if ((type & EFFECT) !== 0) {
+		if (collected_effects !== null) {
+			// created during traversal — collect and run afterwards
+			collected_effects.push(effect);
+		} else {
+			// schedule for later
+			schedule_effect(effect);
+		}
+	} else if (fn !== null) {
 		try {
 			update_effect(effect);
 		} catch (e) {
 			destroy_effect(effect);
 			throw e;
 		}
-	} else if (fn !== null) {
-		schedule_effect(effect);
-	}
 
-	/** @type {Effect | null} */
-	var e = effect;
-
-	// if an effect has already ran and doesn't need to be kept in the tree
-	// (because it won't re-run, has no DOM, and has no teardown etc)
-	// then we skip it and go to its child (if any)
-	if (
-		sync &&
-		e.deps === null &&
-		e.teardown === null &&
-		e.nodes === null &&
-		e.first === e.last && // either `null`, or a singular child
-		(e.f & EFFECT_PRESERVED) === 0
-	) {
-		e = e.first;
-		if ((type & BLOCK_EFFECT) !== 0 && (type & EFFECT_TRANSPARENT) !== 0 && e !== null) {
-			e.f |= EFFECT_TRANSPARENT;
+		// if an effect doesn't need to be kept in the tree (because it
+		// won't re-run, has no DOM, and has no teardown etc)
+		// then we skip it and go to its child (if any)
+		if (
+			e.deps === null &&
+			e.teardown === null &&
+			e.nodes === null &&
+			e.first === e.last && // either `null`, or a singular child
+			(e.f & EFFECT_PRESERVED) === 0
+		) {
+			e = e.first;
+			if ((type & BLOCK_EFFECT) !== 0 && (type & EFFECT_TRANSPARENT) !== 0 && e !== null) {
+				e.f |= EFFECT_TRANSPARENT;
+			}
 		}
 	}
 
@@ -183,7 +187,7 @@ export function effect_tracking() {
  * @param {() => void} fn
  */
 export function teardown(fn) {
-	const effect = create_effect(RENDER_EFFECT, null, false);
+	const effect = create_effect(RENDER_EFFECT, null);
 	set_signal_status(effect, CLEAN);
 	effect.teardown = fn;
 	return effect;
@@ -221,7 +225,7 @@ export function user_effect(fn) {
  * @param {() => void | (() => void)} fn
  */
 export function create_user_effect(fn) {
-	return create_effect(EFFECT | USER_EFFECT, fn, false);
+	return create_effect(EFFECT | USER_EFFECT, fn);
 }
 
 /**
@@ -236,12 +240,12 @@ export function user_pre_effect(fn) {
 			value: '$effect.pre'
 		});
 	}
-	return create_effect(RENDER_EFFECT | USER_EFFECT, fn, true);
+	return create_effect(RENDER_EFFECT | USER_EFFECT, fn);
 }
 
 /** @param {() => void | (() => void)} fn */
 export function eager_effect(fn) {
-	return create_effect(EAGER_EFFECT, fn, true);
+	return create_effect(EAGER_EFFECT, fn);
 }
 
 /**
@@ -251,7 +255,7 @@ export function eager_effect(fn) {
  */
 export function effect_root(fn) {
 	Batch.ensure();
-	const effect = create_effect(ROOT_EFFECT | EFFECT_PRESERVED, fn, true);
+	const effect = create_effect(ROOT_EFFECT | EFFECT_PRESERVED, fn);
 
 	return () => {
 		destroy_effect(effect);
@@ -265,7 +269,7 @@ export function effect_root(fn) {
  */
 export function component_root(fn) {
 	Batch.ensure();
-	const effect = create_effect(ROOT_EFFECT | EFFECT_PRESERVED, fn, true);
+	const effect = create_effect(ROOT_EFFECT | EFFECT_PRESERVED, fn);
 
 	return (options = {}) => {
 		return new Promise((fulfil) => {
@@ -287,7 +291,7 @@ export function component_root(fn) {
  * @returns {Effect}
  */
 export function effect(fn) {
-	return create_effect(EFFECT, fn, false);
+	return create_effect(EFFECT, fn);
 }
 
 /**
@@ -345,7 +349,7 @@ export function legacy_pre_effect_reset() {
  * @returns {Effect}
  */
 export function async_effect(fn) {
-	return create_effect(ASYNC | EFFECT_PRESERVED, fn, true);
+	return create_effect(ASYNC | EFFECT_PRESERVED, fn);
 }
 
 /**
@@ -353,7 +357,7 @@ export function async_effect(fn) {
  * @returns {Effect}
  */
 export function render_effect(fn, flags = 0) {
-	return create_effect(RENDER_EFFECT | flags, fn, true);
+	return create_effect(RENDER_EFFECT | flags, fn);
 }
 
 /**
@@ -364,7 +368,7 @@ export function render_effect(fn, flags = 0) {
  */
 export function template_effect(fn, sync = [], async = [], blockers = []) {
 	flatten(blockers, sync, async, (values) => {
-		create_effect(RENDER_EFFECT, () => fn(...values.map(get)), true);
+		create_effect(RENDER_EFFECT, () => fn(...values.map(get)));
 	});
 }
 
@@ -381,7 +385,7 @@ export function deferred_template_effect(fn, sync = [], async = [], blockers = [
 	}
 
 	flatten(blockers, sync, async, (values) => {
-		create_effect(EFFECT, () => fn(...values.map(get)), false);
+		create_effect(EFFECT, () => fn(...values.map(get)));
 
 		if (decrement_pending) {
 			decrement_pending();
@@ -394,7 +398,7 @@ export function deferred_template_effect(fn, sync = [], async = [], blockers = [
  * @param {number} flags
  */
 export function block(fn, flags = 0) {
-	var effect = create_effect(BLOCK_EFFECT | flags, fn, true);
+	var effect = create_effect(BLOCK_EFFECT | flags, fn);
 	if (DEV) {
 		effect.dev_stack = dev_stack;
 	}
@@ -406,7 +410,7 @@ export function block(fn, flags = 0) {
  * @param {number} flags
  */
 export function managed(fn, flags = 0) {
-	var effect = create_effect(MANAGED_EFFECT | flags, fn, true);
+	var effect = create_effect(MANAGED_EFFECT | flags, fn);
 	if (DEV) {
 		effect.dev_stack = dev_stack;
 	}
@@ -417,7 +421,7 @@ export function managed(fn, flags = 0) {
  * @param {(() => void)} fn
  */
 export function branch(fn) {
-	return create_effect(BRANCH_EFFECT | EFFECT_PRESERVED, fn, true);
+	return create_effect(BRANCH_EFFECT | EFFECT_PRESERVED, fn);
 }
 
 /**
diff --git a/packages/svelte/src/internal/client/render.js b/packages/svelte/src/internal/client/render.js
index 76a73852d5..cb152ed9c1 100644
--- a/packages/svelte/src/internal/client/render.js
+++ b/packages/svelte/src/internal/client/render.js
@@ -45,12 +45,12 @@ export function set_should_intro(value) {
  */
 export function set_text(text, value) {
 	// For objects, we apply string coercion (which might make things like $state array references in the template reactive) before diffing
-	var str = value == null ? '' : typeof value === 'object' ? value + '' : value;
+	var str = value == null ? '' : typeof value === 'object' ? `${value}` : value;
 	// @ts-expect-error
 	if (str !== (text.__t ??= text.nodeValue)) {
 		// @ts-expect-error
 		text.__t = str;
-		text.nodeValue = str + '';
+		text.nodeValue = `${str}`;
 	}
 }
 
@@ -81,6 +81,7 @@ export function mount(component, options) {
  *  	context?: Map<any, any>;
  * 		intro?: boolean;
  * 		recover?: boolean;
+ *		transformError?: (error: unknown) => unknown;
  * 	} : {
  * 		target: Document | Element | ShadowRoot;
  * 		props: Props;
@@ -88,6 +89,7 @@ export function mount(component, options) {
  *  	context?: Map<any, any>;
  * 		intro?: boolean;
  * 		recover?: boolean;
+ *		transformError?: (error: unknown) => unknown;
  * 	}} options
  * @returns {Exports}
  */
@@ -158,7 +160,10 @@ const listeners = new Map();
  * @param {MountOptions} options
  * @returns {Exports}
  */
-function _mount(Component, { target, anchor, props = {}, events, context, intro = true }) {
+function _mount(
+	Component,
+	{ target, anchor, props = {}, events, context, intro = true, transformError }
+) {
 	init_operations();
 
 	/** @type {Exports} */
@@ -206,7 +211,8 @@ function _mount(Component, { target, anchor, props = {}, events, context, intro
 				}
 
 				pop();
-			}
+			},
+			transformError
 		);
 
 		// Setup event delegation _after_ component is mounted - if an error would happen during mount, it would otherwise not be cleaned up
diff --git a/packages/svelte/src/internal/client/runtime.js b/packages/svelte/src/internal/client/runtime.js
index e745f7f137..3260c24b8c 100644
--- a/packages/svelte/src/internal/client/runtime.js
+++ b/packages/svelte/src/internal/client/runtime.js
@@ -752,30 +752,6 @@ export function untrack(fn) {
 	}
 }
 
-/**
- * @param {Record<string | symbol, unknown>} obj
- * @param {Array<string | symbol>} keys
- * @returns {Record<string | symbol, unknown>}
- */
-export function exclude_from_object(obj, keys) {
-	/** @type {Record<string | symbol, unknown>} */
-	var result = {};
-
-	for (var key in obj) {
-		if (!keys.includes(key)) {
-			result[key] = obj[key];
-		}
-	}
-
-	for (var symbol of Object.getOwnPropertySymbols(obj)) {
-		if (Object.propertyIsEnumerable.call(obj, symbol) && !keys.includes(symbol)) {
-			result[symbol] = obj[symbol];
-		}
-	}
-
-	return result;
-}
-
 /**
  * Possibly traverse an object and read all its properties so that they're all reactive in case this is `$state`.
  * Does only check first level of an object for performance reasons (heuristic should be good for 99% of all cases).
diff --git a/packages/svelte/src/internal/server/crypto.js b/packages/svelte/src/internal/server/crypto.js
index 76d66b6d1a..38b5f65892 100644
--- a/packages/svelte/src/internal/server/crypto.js
+++ b/packages/svelte/src/internal/server/crypto.js
@@ -4,6 +4,9 @@ let text_encoder;
 // TODO - remove this and use global `crypto` when we drop Node 18
 let crypto;
 
+/** @param {string} module_name */
+const obfuscated_import = (module_name) => import(/* @vite-ignore */ module_name);
+
 /** @param {string} data */
 export async function sha256(data) {
 	text_encoder ??= new TextEncoder();
@@ -12,8 +15,8 @@ export async function sha256(data) {
 	crypto ??= globalThis.crypto?.subtle?.digest
 		? globalThis.crypto
 		: // @ts-ignore - we don't install node types in the prod build
-			// don't use 'node:crypto' because static analysers will think we rely on node when we don't
-			(await import(/* @vite-ignore */ 'node:' + 'crypto')).webcrypto;
+			// don't use import('node:crypto') directly because static analysers will think we rely on node when we don't
+			(await obfuscated_import('node:crypto')).webcrypto;
 
 	const hash_buffer = await crypto.subtle.digest('SHA-256', text_encoder.encode(data));
 
diff --git a/packages/svelte/src/internal/server/errors.js b/packages/svelte/src/internal/server/errors.js
index c966c32062..d1e594acfd 100644
--- a/packages/svelte/src/internal/server/errors.js
+++ b/packages/svelte/src/internal/server/errors.js
@@ -26,6 +26,19 @@ export function await_invalid() {
 	throw error;
 }
 
+/**
+ * `<svelte:element this="%tag%">` is not a valid element name — the element will not be rendered
+ * @param {string} tag
+ * @returns {never}
+ */
+export function dynamic_element_invalid_tag(tag) {
+	const error = new Error(`dynamic_element_invalid_tag\n\`<svelte:element this="${tag}">\` is not a valid element name — the element will not be rendered\nhttps://svelte.dev/e/dynamic_element_invalid_tag`);
+
+	error.name = 'Svelte error';
+
+	throw error;
+}
+
 /**
  * The `html` property of server render results has been deprecated. Use `body` instead.
  * @returns {never}
diff --git a/packages/svelte/src/internal/server/index.js b/packages/svelte/src/internal/server/index.js
index 015db09a64..70f1f6dab8 100644
--- a/packages/svelte/src/internal/server/index.js
+++ b/packages/svelte/src/internal/server/index.js
@@ -13,11 +13,17 @@ import {
 } from '../../constants.js';
 import { escape_html } from '../../escaping.js';
 import { DEV } from 'esm-env';
-import { EMPTY_COMMENT, BLOCK_CLOSE, BLOCK_OPEN, BLOCK_OPEN_ELSE } from './hydration.js';
+import { EMPTY_COMMENT, BLOCK_OPEN, BLOCK_OPEN_ELSE } from './hydration.js';
 import { validate_store } from '../shared/validate.js';
-import { is_boolean_attribute, is_raw_text_element, is_void } from '../../utils.js';
+import {
+	is_boolean_attribute,
+	is_raw_text_element,
+	is_void,
+	REGEX_VALID_TAG_NAME
+} from '../../utils.js';
 import { Renderer } from './renderer.js';
 import * as e from './errors.js';
+import { ssr_context } from './context.js';
 
 // https://html.spec.whatwg.org/multipage/syntax.html#attributes-2
 // https://infra.spec.whatwg.org/#noncharacter
@@ -35,6 +41,9 @@ export function element(renderer, tag, attributes_fn = noop, children_fn = noop)
 	renderer.push('<!---->');
 
 	if (tag) {
+		if (!REGEX_VALID_TAG_NAME.test(tag)) {
+			e.dynamic_element_invalid_tag(tag);
+		}
 		renderer.push(`<${tag}`);
 		attributes_fn();
 		renderer.push(`>`);
@@ -56,7 +65,7 @@ export function element(renderer, tag, attributes_fn = noop, children_fn = noop)
  * Takes a component and returns an object with `body` and `head` properties on it, which you can use to populate the HTML when server-rendering your app.
  * @template {Record<string, any>} Props
  * @param {Component<Props> | ComponentType<SvelteComponent<Props>>} component
- * @param {{ props?: Omit<Props, '$$slots' | '$$events'>; context?: Map<any, any>; idPrefix?: string; csp?: Csp }} [options]
+ * @param {{ props?: Omit<Props, '$$slots' | '$$events'>; context?: Map<any, any>; idPrefix?: string; csp?: Csp; transformError?: (error: unknown) => unknown }} [options]
  * @returns {RenderOutput}
  */
 export function render(component, options = {}) {
@@ -97,16 +106,16 @@ export function css_props(renderer, is_html, props, component, dynamic = false)
 		renderer.push(`<g style="${styles}">`);
 	}
 
-	if (dynamic) {
+	component();
+
+	if (!dynamic) {
 		renderer.push('<!---->');
 	}
 
-	component();
-
 	if (is_html) {
-		renderer.push(`<!----></svelte-css-wrapper>`);
+		renderer.push('</svelte-css-wrapper>');
 	} else {
-		renderer.push(`<!----></g>`);
+		renderer.push('</g>');
 	}
 }
 
@@ -138,7 +147,7 @@ export function attributes(attrs, css_hash, classes, styles, flags = 0) {
 	const lowercase = (flags & ELEMENT_PRESERVE_ATTRIBUTE_CASE) === 0;
 	const is_input = (flags & ELEMENT_IS_INPUT) !== 0;
 
-	for (name in attrs) {
+	for (name of Object.keys(attrs)) {
 		// omit functions, internal svelte properties and invalid attribute names
 		if (typeof attrs[name] === 'function') continue;
 		if (name[0] === '$' && name[1] === '$') continue; // faster than name.startsWith('$$')
@@ -150,6 +159,9 @@ export function attributes(attrs, css_hash, classes, styles, flags = 0) {
 			name = name.toLowerCase();
 		}
 
+		// omit event handler attributes
+		if (name.length > 2 && name.startsWith('on')) continue;
+
 		if (is_input) {
 			if (name === 'defaultvalue' || name === 'defaultchecked') {
 				name = name === 'defaultvalue' ? 'value' : 'checked';
@@ -174,7 +186,8 @@ export function spread_props(props) {
 
 	for (let i = 0; i < props.length; i++) {
 		const obj = props[i];
-		for (key in obj) {
+		if (obj == null) continue;
+		for (key of Object.keys(obj)) {
 			const desc = Object.getOwnPropertyDescriptor(obj, key);
 			if (desc) {
 				Object.defineProperty(merged_props, key, desc);
@@ -302,7 +315,7 @@ export function update_store_pre(store_values, store_name, store, d = 1) {
 
 /** @param {Record<string, [any, any, any]>} store_values */
 export function unsubscribe_stores(store_values) {
-	for (const store_name in store_values) {
+	for (const store_name of Object.keys(store_values)) {
 		store_values[store_name][1]();
 	}
 }
@@ -338,7 +351,7 @@ export function rest_props(props, rest) {
 	/** @type {Record<string, unknown>} */
 	const rest_props = {};
 	let key;
-	for (key in props) {
+	for (key of Object.keys(props)) {
 		if (!rest.includes(key)) {
 			rest_props[key] = props[key];
 		}
@@ -363,7 +376,7 @@ export function sanitize_slots(props) {
 	/** @type {Record<string, boolean>} */
 	const sanitized = {};
 	if (props.children) sanitized.default = true;
-	for (const key in props.$$slots) {
+	for (const key of Object.keys(props.$$slots || {})) {
 		sanitized[key] = true;
 	}
 	return sanitized;
@@ -376,7 +389,7 @@ export function sanitize_slots(props) {
  * @param {Record<string, unknown>} props_now
  */
 export function bind_props(props_parent, props_now) {
-	for (const key in props_now) {
+	for (const key of Object.keys(props_now)) {
 		const initial_value = props_parent[key];
 		const value = props_now[key];
 		if (
@@ -457,7 +470,7 @@ export { push_element, pop_element, validate_snippet_args } from './dev.js';
 
 export { snapshot } from '../shared/clone.js';
 
-export { fallback, to_array } from '../shared/utils.js';
+export { fallback, to_array, exclude_from_object } from '../shared/utils.js';
 
 export {
 	invalid_default_snippet,
@@ -474,17 +487,58 @@ export { escape_html as escape };
  * @returns {(new_value?: T) => (T | void)}
  */
 export function derived(fn) {
-	const get_value = once(fn);
-	/**
-	 * @type {T | undefined}
-	 */
+	// deriveds created during render are memoized,
+	// deriveds created outside (e.g. SvelteKit `page` stuff) are not
+	const get_value = ssr_context === null ? fn : once(fn);
+
+	/** @type {T | undefined} */
 	let updated_value;
 
 	return function (new_value) {
 		if (arguments.length === 0) {
 			return updated_value ?? get_value();
 		}
+
 		updated_value = new_value;
 		return updated_value;
 	};
 }
+
+/**
+ * @template {number | bigint} T
+ * @param {(value?: T) => T} derived
+ * @param {1 | -1} [d]
+ * @returns {T}
+ */
+export function update_derived(derived, d = 1) {
+	const value = derived();
+	let increase = typeof value === 'bigint' ? BigInt(d) : d;
+	// for some reason TS is mad even if T is always number or bigint
+	derived(value + /** @type {*} */ (increase));
+	return value;
+}
+
+/**
+ * @template {number | bigint} T
+ * @param {(value?: T) => T} derived
+ * @param {1 | -1} [d]
+ * @returns {T}
+ */
+export function update_derived_pre(derived, d = 1) {
+	const old_value = derived();
+	let increase = typeof old_value === 'bigint' ? BigInt(d) : d;
+	// for some reason TS is mad even if T is always number or bigint
+	const value = old_value + /** @type {*} */ (increase);
+	derived(value);
+	return value;
+}
+
+/**
+ * @template T
+ * @param {()=>T} fn
+ */
+export function async_derived(fn) {
+	return Promise.resolve(fn()).then((value) => {
+		return () => value;
+	});
+}
diff --git a/packages/svelte/src/internal/server/renderer.js b/packages/svelte/src/internal/server/renderer.js
index d18a48bdb4..da65811eca 100644
--- a/packages/svelte/src/internal/server/renderer.js
+++ b/packages/svelte/src/internal/server/renderer.js
@@ -3,15 +3,17 @@
 /** @import { MaybePromise } from '#shared' */
 import { async_mode_flag } from '../flags/index.js';
 import { abort } from './abort-signal.js';
-import { pop, push, set_ssr_context, ssr_context, save } from './context.js';
+import { pop, push, set_ssr_context, ssr_context } from './context.js';
 import * as e from './errors.js';
 import * as w from './warnings.js';
 import { BLOCK_CLOSE, BLOCK_OPEN } from './hydration.js';
+import { HYDRATION_START_FAILED } from '../../constants.js';
 import { attributes } from './index.js';
 import { get_render_context, with_render_context, init_render_context } from './render-context.js';
 import { sha256 } from './crypto.js';
 import * as devalue from 'devalue';
-import { noop } from '../shared/utils.js';
+import { has_own_property, noop } from '../shared/utils.js';
+import { escape_html } from '../../escaping.js';
 
 /** @typedef {'head' | 'body'} RendererType */
 /** @typedef {{ [key in RendererType]: string }} AccumulatedContent */
@@ -48,6 +50,17 @@ export class Renderer {
 	 */
 	#is_component_body = false;
 
+	/**
+	 * If set, this renderer is an error boundary. When async collection
+	 * of the children fails, the failed snippet is rendered instead.
+	 * @type {{
+	 * 	failed: (renderer: Renderer, error: unknown, reset: () => void) => void;
+	 * 	transformError: (error: unknown) => unknown;
+	 * 	context: SSRContext | null;
+	 * } | null}
+	 */
+	#boundary = null;
+
 	/**
 	 * The type of string content that this renderer is accumulating.
 	 * @type {RendererType}
@@ -203,17 +216,97 @@ export class Renderer {
 		set_ssr_context(parent);
 
 		if (result instanceof Promise) {
+			// catch to avoid unhandled promise rejections - we'll end up throwing in `collect_async` if something fails
+			result.catch(noop);
+			result.finally(() => set_ssr_context(null)).catch(noop);
+
 			if (child.global.mode === 'sync') {
 				e.await_invalid();
 			}
-			// just to avoid unhandled promise rejections -- we'll end up throwing in `collect_async` if something fails
-			result.catch(() => {});
+
 			child.promise = result;
 		}
 
 		return child;
 	}
 
+	/**
+	 * Render children inside an error boundary. If the children throw and the API-level
+	 * `transformError` transform handles the error (doesn't re-throw), the `failed` snippet is
+	 * rendered instead. Otherwise the error propagates.
+	 *
+	 * @param {{ failed?: (renderer: Renderer, error: unknown, reset: () => void) => void }} props
+	 * @param {(renderer: Renderer) => MaybePromise<void>} children_fn
+	 */
+	boundary(props, children_fn) {
+		// Create a child renderer for the boundary content.
+		// Mark it as a boundary so that #collect_content_async can catch
+		// errors from nested async children and render the failed snippet.
+		const child = new Renderer(this.global, this);
+		this.#out.push(child);
+
+		const parent_context = ssr_context;
+
+		if (props.failed) {
+			child.#boundary = {
+				failed: props.failed,
+				transformError: this.global.transformError,
+				context: parent_context
+			};
+		}
+
+		set_ssr_context({
+			...ssr_context,
+			p: parent_context,
+			c: null,
+			r: child
+		});
+
+		try {
+			const result = children_fn(child);
+
+			set_ssr_context(parent_context);
+
+			if (result instanceof Promise) {
+				if (child.global.mode === 'sync') {
+					e.await_invalid();
+				}
+				result.catch(noop);
+				child.promise = result;
+			}
+		} catch (error) {
+			// synchronous errors are handled here, async errors will be handled in #collect_content_async
+			set_ssr_context(parent_context);
+
+			const failed_snippet = props.failed;
+
+			if (!failed_snippet) throw error;
+
+			const result = this.global.transformError(error);
+
+			child.#out.length = 0;
+			child.#boundary = null;
+
+			if (result instanceof Promise) {
+				if (this.global.mode === 'sync') {
+					e.await_invalid();
+				}
+
+				child.promise = /** @type {Promise<unknown>} */ (result).then((transformed) => {
+					set_ssr_context(parent_context);
+					child.#out.push(Renderer.#serialize_failed_boundary(transformed));
+					failed_snippet(child, transformed, noop);
+					child.#out.push(BLOCK_CLOSE);
+				});
+				child.promise.catch(noop);
+			} else {
+				child.#out.push(Renderer.#serialize_failed_boundary(result));
+				failed_snippet(child, result, noop);
+				child.#out.push(BLOCK_CLOSE);
+			}
+		}
+	}
+
 	/**
 	 * Create a component renderer. The component renderer inherits the state from the parent,
 	 * but has its own content. It is treated as an ordering boundary for ondestroy callbacks.
@@ -267,7 +360,7 @@ export class Renderer {
 		 * @param {{ head?: string, body: any }} content
 		 */
 		const close = (renderer, value, { head, body }) => {
-			if ('value' in attrs) {
+			if (has_own_property.call(attrs, 'value')) {
 				value = attrs.value;
 			}
 
@@ -298,7 +391,7 @@ export class Renderer {
 				}
 			});
 		} else {
-			close(this, body, { body });
+			close(this, body, { body: escape_html(body) });
 		}
 	}
 
@@ -389,6 +482,21 @@ export class Renderer {
 		return this.#out.length;
 	}
 
+	/**
+	 * Creates the hydration comment that marks the start of a failed boundary.
+	 * The error is JSON-serialized and embedded inside an HTML comment for the client
+	 * to parse during hydration. The JSON is escaped to prevent `-->` or `<!--` sequences
+	 * from breaking out of the comment (XSS). Uses unicode escapes which `JSON.parse()`
+	 * handles transparently.
+	 * @param {unknown} error
+	 * @returns {string}
+	 */
+	static #serialize_failed_boundary(error) {
+		var json = JSON.stringify(error);
+		var escaped = json.replace(/>/g, '\\u003e').replace(/</g, '\\u003c');
+		return `<!--${HYDRATION_START_FAILED}${escaped}-->`;
+	}
+
 	/**
 	 * Only available on the server and when compiling with the `server` option.
 	 * Takes a component and returns an object with `body` and `head` properties on it, which you can use to populate the HTML when server-rendering your app.
@@ -588,7 +696,34 @@ export class Renderer {
 			if (typeof item === 'string') {
 				content[this.type] += item;
 			} else if (item instanceof Renderer) {
-				await item.#collect_content_async(content);
+				if (item.#boundary) {
+					// This renderer is an error boundary - collect into a separate
+					// accumulator so we can discard partial content on error
+					/** @type {AccumulatedContent} */
+					const boundary_content = { head: '', body: '' };
+
+					try {
+						await item.#collect_content_async(boundary_content);
+						// Success - merge into the main content
+						content.head += boundary_content.head;
+						content.body += boundary_content.body;
+					} catch (error) {
+						const { context, failed, transformError } = item.#boundary;
+
+						set_ssr_context(context);
+						let transformed = await transformError(error);
+
+						// Render the failed snippet instead of the partial children content
+						const failed_renderer = new Renderer(item.global, item);
+						failed_renderer.type = item.type;
+						failed_renderer.#out.push(Renderer.#serialize_failed_boundary(transformed));
+						failed(failed_renderer, transformed, noop);
+						failed_renderer.#out.push(BLOCK_CLOSE);
+						await failed_renderer.#collect_content_async(content);
+					}
+				} else {
+					await item.#collect_content_async(content);
+				}
 			}
 		}
 
@@ -616,28 +751,35 @@ export class Renderer {
 	 * @template {Record<string, any>} Props
 	 * @param {'sync' | 'async'} mode
 	 * @param {import('svelte').Component<Props>} component
-	 * @param {{ props?: Omit<Props, '$$slots' | '$$events'>; context?: Map<any, any>; idPrefix?: string; csp?: Csp }} options
+	 * @param {{ props?: Omit<Props, '$$slots' | '$$events'>; context?: Map<any, any>; idPrefix?: string; csp?: Csp; transformError?: (error: unknown) => unknown }} options
 	 * @returns {Renderer}
 	 */
 	static #open_render(mode, component, options) {
-		const renderer = new Renderer(
-			new SSRState(mode, options.idPrefix ? options.idPrefix + '-' : '', options.csp)
-		);
-
-		renderer.push(BLOCK_OPEN);
-
-		push();
-		if (options.context) /** @type {SSRContext} */ (ssr_context).c = options.context;
-		/** @type {SSRContext} */ (ssr_context).r = renderer;
+		var previous_context = ssr_context;
 
-		// @ts-expect-error
-		component(renderer, options.props ?? {});
+		try {
+			const renderer = new Renderer(
+				new SSRState(
+					mode,
+					options.idPrefix ? options.idPrefix + '-' : '',
+					options.csp,
+					options.transformError
+				)
+			);
 
-		pop();
+			/** @type {SSRContext} */
+			const context = { p: null, c: options.context ?? null, r: renderer };
+			set_ssr_context(context);
 
-		renderer.push(BLOCK_CLOSE);
+			renderer.push(BLOCK_OPEN);
+			// @ts-expect-error
+			component(renderer, options.props ?? {});
+			renderer.push(BLOCK_CLOSE);
 
-		return renderer;
+			return renderer;
+		} finally {
+			set_ssr_context(previous_context);
+		}
 	}
 
 	/**
@@ -733,6 +875,13 @@ export class SSRState {
 	/** @readonly @type {Set<{ hash: string; code: string }>} */
 	css = new Set();
 
+	/**
+	 * `transformError` passed to `render`. Called when an error boundary catches an error.
+	 * Throws by default if unset in `render`.
+	 * @type {(error: unknown) => unknown}
+	 */
+	transformError;
+
 	/** @type {{ path: number[], value: string }} */
 	#title = { path: [], value: '' };
 
@@ -740,11 +889,18 @@ export class SSRState {
 	 * @param {'sync' | 'async'} mode
 	 * @param {string} id_prefix
 	 * @param {Csp} csp
+	 * @param {((error: unknown) => unknown) | undefined} [transformError]
 	 */
-	constructor(mode, id_prefix = '', csp = { hash: false }) {
+	constructor(mode, id_prefix = '', csp = { hash: false }, transformError) {
 		this.mode = mode;
 		this.csp = { ...csp, script_hashes: [] };
 
+		this.transformError =
+			transformError ??
+			((error) => {
+				throw error;
+			});
+
 		let uid = 1;
 		this.uid = () => `${id_prefix}s${uid++}`;
 	}
diff --git a/packages/svelte/src/internal/server/renderer.test.ts b/packages/svelte/src/internal/server/renderer.test.ts
index bbbe3f745d..8e98c41796 100644
--- a/packages/svelte/src/internal/server/renderer.test.ts
+++ b/packages/svelte/src/internal/server/renderer.test.ts
@@ -225,6 +225,118 @@ test('select merges scoped css hash with static class', () => {
 	);
 });
 
+describe('boundary hydration comment escaping', () => {
+	const failed_snippet = (renderer: Renderer, error: unknown) => {
+		renderer.push(`<p>${(error as { message: string }).message}</p>`);
+	};
+
+	const transform = (error: unknown) => ({ message: (error as Error).message });
+
+	const payloads = [
+		{
+			name: 'escapes -->',
+			input: '--><img src=x onerror=alert(1)><!--',
+			expected: '{"message":"--\\u003e\\u003cimg src=x onerror=alert(1)\\u003e\\u003c!--"}'
+		},
+		{
+			name: 'escapes <!--',
+			input: '<!--<script>alert(1)</script>',
+			expected: '{"message":"\\u003c!--\\u003cscript\\u003ealert(1)\\u003c/script\\u003e"}'
+		},
+		{ name: 'escapes <!-->', input: '<!-->', expected: '{"message":"\\u003c!--\\u003e"}' },
+		{ name: 'escapes <!--->', input: '<!--->', expected: '{"message":"\\u003c!---\\u003e"}' },
+		{
+			name: 'escapes multiple -->',
+			input: '-->one-->two-->',
+			expected: '{"message":"--\\u003eone--\\u003etwo--\\u003e"}'
+		},
+		{ name: 'escapes --->', input: '--->', expected: '{"message":"---\\u003e"}' },
+		{ name: 'no double-encoding', input: '--\\u003e', expected: '{"message":"--\\\\u003e"}' },
+		{
+			name: 'the terrifying special pointy boy',
+			input: '--!>ooh, what an exotic closing comment tag',
+			expected: '{"message":"--!\\u003eooh, what an exotic closing comment tag"}'
+		}
+	];
+
+	type RenderFn = (input: string) => Promise<string> | string;
+
+	const paths: Array<{ path: string; async: boolean; render: RenderFn }> = [
+		{
+			path: 'sync children, sync transformError',
+			async: false,
+			render: (input) => {
+				const component = (renderer: Renderer) => {
+					renderer.boundary({ failed: failed_snippet }, () => {
+						throw new Error(input);
+					});
+				};
+				return Renderer.render(
+					component as unknown as Component,
+					{ transformError: transform } as any
+				).body;
+			}
+		},
+		{
+			path: 'sync children, async transformError',
+			async: true,
+			render: async (input) => {
+				const component = (renderer: Renderer) => {
+					renderer.boundary({ failed: failed_snippet }, () => {
+						throw new Error(input);
+					});
+				};
+				return (
+					await Renderer.render(
+						component as unknown as Component,
+						{
+							transformError: (error: unknown) => Promise.resolve(transform(error))
+						} as any
+					)
+				).body;
+			}
+		},
+		{
+			path: 'async children throw',
+			async: true,
+			render: async (input) => {
+				const component = (renderer: Renderer) => {
+					renderer.boundary({ failed: failed_snippet }, async () => {
+						await Promise.resolve();
+						throw new Error(input);
+					});
+				};
+				return (
+					await Renderer.render(
+						component as unknown as Component,
+						{
+							transformError: transform
+						} as any
+					)
+				).body;
+			}
+		}
+	];
+
+	describe.each(paths)('$path', ({ async: needs_async, render }) => {
+		if (needs_async) {
+			beforeAll(() => enable_async_mode_flag());
+			afterAll(() => disable_async_mode_flag());
+		}
+
+		test.each(payloads)('$name', async ({ input, expected }) => {
+			const body = await render(input);
+
+			// Extract the content between <!--[? and the first -->
+			// If escaping is broken, an unescaped --> in the JSON will truncate
+			// the match and the content won't equal the expected escaped JSON.
+			const match = body.match(/<!--\[\?(.+?)-->/);
+			expect(match, 'expected a hydration comment in output').toBeTruthy();
+			expect(match![1]).toBe(expected);
+		});
+	});
+});
+
 describe('async', () => {
 	beforeAll(() => {
 		enable_async_mode_flag();
diff --git a/packages/svelte/src/internal/shared/attributes.js b/packages/svelte/src/internal/shared/attributes.js
index 8bfa91f80c..487a40baf3 100644
--- a/packages/svelte/src/internal/shared/attributes.js
+++ b/packages/svelte/src/internal/shared/attributes.js
@@ -1,5 +1,6 @@
 import { escape_html } from '../../escaping.js';
 import { clsx as _clsx } from 'clsx';
+import { has_own_property } from './utils.js';
 
 /**
  * `<div translate={false}>` should be rendered as `<div translate="no">` and _not_
@@ -27,7 +28,8 @@ export function attr(name, value, is_boolean = false) {
 		is_boolean = true;
 	}
 	if (value == null || (!value && is_boolean)) return '';
-	const normalized = (name in replacements && replacements[name].get(value)) || value;
+	const normalized =
+		(has_own_property.call(replacements, name) && replacements[name].get(value)) || value;
 	const assignment = is_boolean ? `=""` : `="${escape_html(normalized, true)}"`;
 	return ` ${name}${assignment}`;
 }
@@ -61,7 +63,7 @@ export function to_class(value, hash, directives) {
 	}
 
 	if (directives) {
-		for (var key in directives) {
+		for (var key of Object.keys(directives)) {
 			if (directives[key]) {
 				classname = classname ? classname + ' ' + key : key;
 			} else if (classname.length) {
@@ -96,7 +98,7 @@ function append_styles(styles, important = false) {
 	var separator = important ? ' !important;' : ';';
 	var css = '';
 
-	for (var key in styles) {
+	for (var key of Object.keys(styles)) {
 		var value = styles[key];
 		if (value != null && value !== '') {
 			css += ' ' + key + ': ' + value + separator;
diff --git a/packages/svelte/src/internal/shared/clone.js b/packages/svelte/src/internal/shared/clone.js
index b8f99ee198..1a83adf8c5 100644
--- a/packages/svelte/src/internal/shared/clone.js
+++ b/packages/svelte/src/internal/shared/clone.js
@@ -89,7 +89,7 @@ function clone(value, cloned, path, paths, original = null, no_tojson = false) {
 				cloned.set(original, copy);
 			}
 
-			for (var key in value) {
+			for (var key of Object.keys(value)) {
 				copy[key] = clone(
 					// @ts-expect-error
 					value[key],
diff --git a/packages/svelte/src/internal/shared/utils.js b/packages/svelte/src/internal/shared/utils.js
index 771f6b345c..393b51383e 100644
--- a/packages/svelte/src/internal/shared/utils.js
+++ b/packages/svelte/src/internal/shared/utils.js
@@ -12,6 +12,7 @@ export var object_prototype = Object.prototype;
 export var array_prototype = Array.prototype;
 export var get_prototype_of = Object.getPrototypeOf;
 export var is_extensible = Object.isExtensible;
+export var has_own_property = Object.prototype.hasOwnProperty;
 
 /**
  * @param {any} thing
@@ -117,3 +118,27 @@ export function to_array(value, n) {
 
 	return array;
 }
+
+/**
+ * @param {Record<string | symbol, unknown>} obj
+ * @param {Array<string | symbol>} keys
+ * @returns {Record<string | symbol, unknown>}
+ */
+export function exclude_from_object(obj, keys) {
+	/** @type {Record<string | symbol, unknown>} */
+	var result = {};
+
+	for (var key in obj) {
+		if (!keys.includes(key)) {
+			result[key] = obj[key];
+		}
+	}
+
+	for (var symbol of Object.getOwnPropertySymbols(obj)) {
+		if (Object.propertyIsEnumerable.call(obj, symbol) && !keys.includes(symbol)) {
+			result[symbol] = obj[symbol];
+		}
+	}
+
+	return result;
+}
diff --git a/packages/svelte/src/legacy/legacy-client.js b/packages/svelte/src/legacy/legacy-client.js
index ec90d2312c..801c126b2c 100644
--- a/packages/svelte/src/legacy/legacy-client.js
+++ b/packages/svelte/src/legacy/legacy-client.js
@@ -119,7 +119,8 @@ class Svelte4Component {
 			props,
 			context: options.context,
 			intro: options.intro ?? false,
-			recover: options.recover
+			recover: options.recover,
+			transformError: options.transformError
 		});
 
 		// We don't flushSync for custom element wrappers or if the user doesn't want it,
diff --git a/packages/svelte/src/legacy/legacy-server.js b/packages/svelte/src/legacy/legacy-server.js
index 05b329bea1..2c43aab6ac 100644
--- a/packages/svelte/src/legacy/legacy-server.js
+++ b/packages/svelte/src/legacy/legacy-server.js
@@ -25,10 +25,10 @@ export { createClassComponent };
  */
 export function asClassComponent(component) {
 	const component_constructor = as_class_component(component);
-	/** @type {(props?: {}, opts?: { $$slots?: {}; context?: Map<any, any>; csp?: Csp }) => LegacyRenderResult & PromiseLike<LegacyRenderResult> } */
-	const _render = (props, { context, csp } = {}) => {
+	/** @type {(props?: {}, opts?: { $$slots?: {}; context?: Map<any, any>; csp?: Csp; transformError?: (error: unknown) => unknown }) => LegacyRenderResult & PromiseLike<LegacyRenderResult> } */
+	const _render = (props, { context, csp, transformError } = {}) => {
 		// @ts-expect-error the typings are off, but this will work if the component is compiled in SSR mode
-		const result = render(component, { props, context, csp });
+		const result = render(component, { props, context, csp, transformError });
 
 		const munged = Object.defineProperties(
 			/** @type {LegacyRenderResult & PromiseLike<LegacyRenderResult>} */ ({}),
diff --git a/packages/svelte/src/server/index.d.ts b/packages/svelte/src/server/index.d.ts
index f54bd5a5ca..db75afb9ed 100644
--- a/packages/svelte/src/server/index.d.ts
+++ b/packages/svelte/src/server/index.d.ts
@@ -17,6 +17,7 @@ export function render<
 					context?: Map<any, any>;
 					idPrefix?: string;
 					csp?: Csp;
+					transformError?: (error: unknown) => unknown | Promise<unknown>;
 				}
 			]
 		: [
@@ -26,6 +27,7 @@ export function render<
 					context?: Map<any, any>;
 					idPrefix?: string;
 					csp?: Csp;
+					transformError?: (error: unknown) => unknown | Promise<unknown>;
 				}
 			]
 ): RenderOutput;
diff --git a/packages/svelte/src/utils.js b/packages/svelte/src/utils.js
index d63d4ff801..57561e6dc7 100644
--- a/packages/svelte/src/utils.js
+++ b/packages/svelte/src/utils.js
@@ -480,6 +480,19 @@ export function is_raw_text_element(name) {
 	return RAW_TEXT_ELEMENTS.includes(/** @type {typeof RAW_TEXT_ELEMENTS[number]} */ (name));
 }
 
+// Matches valid HTML/SVG/MathML element names and custom element names.
+// https://html.spec.whatwg.org/multipage/custom-elements.html#valid-custom-element-name
+//
+// Standard elements: ASCII alpha start, followed by ASCII alphanumerics.
+// Custom elements: ASCII alpha start, followed by any mix of PCENChar (which
+// includes ASCII alphanumerics, `-`, `.`, `_`, and specified Unicode ranges),
+// with at least one hyphen required somewhere after the first character.
+//
+// Rejects strings containing whitespace, quotes, angle brackets, slashes, equals,
+// or other characters that could break out of a tag-name token and enable markup injection.
+export const REGEX_VALID_TAG_NAME =
+	/^[a-zA-Z][a-zA-Z0-9]*(-[a-zA-Z0-9.\-_\u00B7\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u037D\u037F-\u1FFF\u200C-\u200D\u203F-\u2040\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD\u{10000}-\u{EFFFF}]+)*$/u;
+
 /**
  * Prevent devtools trying to make `location` a clickable link by inserting a zero-width space
  * @template {string | undefined} T
diff --git a/packages/svelte/src/version.js b/packages/svelte/src/version.js
index c27b247dba..61acfc51e3 100644
--- a/packages/svelte/src/version.js
+++ b/packages/svelte/src/version.js
@@ -4,5 +4,5 @@
  * The current version, as set in package.json.
  * @type {string}
  */
-export const VERSION = '5.51.3';
+export const VERSION = '5.53.5';
 export const PUBLIC_VERSION = '5';
diff --git a/packages/svelte/tests/parser-legacy/samples/javascript-comments/output.json b/packages/svelte/tests/parser-legacy/samples/javascript-comments/output.json
index 3775c48228..4d7cb2397f 100644
--- a/packages/svelte/tests/parser-legacy/samples/javascript-comments/output.json
+++ b/packages/svelte/tests/parser-legacy/samples/javascript-comments/output.json
@@ -880,5 +880,423 @@
 			],
 			"sourceType": "module"
 		}
-	}
+	},
+	"_comments": [
+		{
+			"type": "Line",
+			"value": " a leading comment",
+			"start": 10,
+			"end": 30,
+			"loc": {
+				"start": {
+					"line": 2,
+					"column": 1
+				},
+				"end": {
+					"line": 2,
+					"column": 21
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " a trailing comment",
+			"start": 45,
+			"end": 66,
+			"loc": {
+				"start": {
+					"line": 3,
+					"column": 14
+				},
+				"end": {
+					"line": 3,
+					"column": 35
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": "* a comment ",
+			"start": 83,
+			"end": 99,
+			"loc": {
+				"start": {
+					"line": 6,
+					"column": 1
+				},
+				"end": {
+					"line": 6,
+					"column": 17
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " trailing",
+			"start": 125,
+			"end": 136,
+			"loc": {
+				"start": {
+					"line": 8,
+					"column": 7
+				},
+				"end": {
+					"line": 8,
+					"column": 18
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " leading comment 1 ",
+			"start": 139,
+			"end": 162,
+			"loc": {
+				"start": {
+					"line": 9,
+					"column": 2
+				},
+				"end": {
+					"line": 9,
+					"column": 25
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " leading comment 2 ",
+			"start": 165,
+			"end": 188,
+			"loc": {
+				"start": {
+					"line": 10,
+					"column": 2
+				},
+				"end": {
+					"line": 10,
+					"column": 25
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " leading comment 3 ",
+			"start": 191,
+			"end": 214,
+			"loc": {
+				"start": {
+					"line": 11,
+					"column": 2
+				},
+				"end": {
+					"line": 11,
+					"column": 25
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " trailing comment 1 ",
+			"start": 224,
+			"end": 248,
+			"loc": {
+				"start": {
+					"line": 13,
+					"column": 2
+				},
+				"end": {
+					"line": 13,
+					"column": 26
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " trailing comment 2 ",
+			"start": 251,
+			"end": 275,
+			"loc": {
+				"start": {
+					"line": 14,
+					"column": 2
+				},
+				"end": {
+					"line": 14,
+					"column": 26
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " trailing comment 3 ",
+			"start": 278,
+			"end": 302,
+			"loc": {
+				"start": {
+					"line": 15,
+					"column": 2
+				},
+				"end": {
+					"line": 15,
+					"column": 26
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " leading comment 1",
+			"start": 326,
+			"end": 346,
+			"loc": {
+				"start": {
+					"line": 19,
+					"column": 2
+				},
+				"end": {
+					"line": 19,
+					"column": 22
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " leading comment 2",
+			"start": 349,
+			"end": 369,
+			"loc": {
+				"start": {
+					"line": 20,
+					"column": 2
+				},
+				"end": {
+					"line": 20,
+					"column": 22
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " trailing comment 1",
+			"start": 375,
+			"end": 396,
+			"loc": {
+				"start": {
+					"line": 21,
+					"column": 5
+				},
+				"end": {
+					"line": 21,
+					"column": 26
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " trailing comment 2 ",
+			"start": 399,
+			"end": 423,
+			"loc": {
+				"start": {
+					"line": 22,
+					"column": 2
+				},
+				"end": {
+					"line": 22,
+					"column": 26
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " leading comment 1",
+			"start": 449,
+			"end": 469,
+			"loc": {
+				"start": {
+					"line": 26,
+					"column": 2
+				},
+				"end": {
+					"line": 26,
+					"column": 22
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " leading comment 2",
+			"start": 472,
+			"end": 492,
+			"loc": {
+				"start": {
+					"line": 27,
+					"column": 2
+				},
+				"end": {
+					"line": 27,
+					"column": 22
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " trailing comment 1",
+			"start": 501,
+			"end": 522,
+			"loc": {
+				"start": {
+					"line": 28,
+					"column": 8
+				},
+				"end": {
+					"line": 28,
+					"column": 29
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " trailing comment 2 ",
+			"start": 525,
+			"end": 549,
+			"loc": {
+				"start": {
+					"line": 29,
+					"column": 2
+				},
+				"end": {
+					"line": 29,
+					"column": 26
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " comment",
+			"start": 584,
+			"end": 594,
+			"loc": {
+				"start": {
+					"line": 34,
+					"column": 11
+				},
+				"end": {
+					"line": 34,
+					"column": 21
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " another comment ",
+			"start": 606,
+			"end": 627,
+			"loc": {
+				"start": {
+					"line": 36,
+					"column": 2
+				},
+				"end": {
+					"line": 36,
+					"column": 23
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " a trailing comment",
+			"start": 636,
+			"end": 657,
+			"loc": {
+				"start": {
+					"line": 37,
+					"column": 8
+				},
+				"end": {
+					"line": 37,
+					"column": 29
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " trailing block comment ",
+			"start": 660,
+			"end": 688,
+			"loc": {
+				"start": {
+					"line": 38,
+					"column": 2
+				},
+				"end": {
+					"line": 38,
+					"column": 30
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " leading block comment ",
+			"start": 696,
+			"end": 723,
+			"loc": {
+				"start": {
+					"line": 41,
+					"column": 1
+				},
+				"end": {
+					"line": 41,
+					"column": 28
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " leading line comment",
+			"start": 739,
+			"end": 762,
+			"loc": {
+				"start": {
+					"line": 43,
+					"column": 2
+				},
+				"end": {
+					"line": 43,
+					"column": 25
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"value": " trailing line comment",
+			"start": 770,
+			"end": 794,
+			"loc": {
+				"start": {
+					"line": 44,
+					"column": 7
+				},
+				"end": {
+					"line": 44,
+					"column": 31
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"value": " trailing block comment ",
+			"start": 796,
+			"end": 824,
+			"loc": {
+				"start": {
+					"line": 45,
+					"column": 1
+				},
+				"end": {
+					"line": 45,
+					"column": 29
+				}
+			}
+		}
+	]
 }
diff --git a/packages/svelte/tests/parser-legacy/samples/script-comment-only/output.json b/packages/svelte/tests/parser-legacy/samples/script-comment-only/output.json
index 0f7d0b8465..8ec0e0cd65 100644
--- a/packages/svelte/tests/parser-legacy/samples/script-comment-only/output.json
+++ b/packages/svelte/tests/parser-legacy/samples/script-comment-only/output.json
@@ -51,5 +51,23 @@
 				}
 			]
 		}
-	}
+	},
+	"_comments": [
+		{
+			"type": "Line",
+			"value": " TODO write some code",
+			"start": 10,
+			"end": 33,
+			"loc": {
+				"start": {
+					"line": 2,
+					"column": 1
+				},
+				"end": {
+					"line": 2,
+					"column": 24
+				}
+			}
+		}
+	]
 }
diff --git a/packages/svelte/tests/parser-modern/samples/comment-in-tag/input.svelte b/packages/svelte/tests/parser-modern/samples/comment-in-tag/input.svelte
new file mode 100644
index 0000000000..3070aeb178
--- /dev/null
+++ b/packages/svelte/tests/parser-modern/samples/comment-in-tag/input.svelte
@@ -0,0 +1,22 @@
+<div
+	data-one="1"
+	// this is a line comment
+	data-two="2"
+	/* this is a
+		m
+		u
+		l
+		t
+		i
+		l
+		i
+		n
+		e
+		comment
+	*/
+	// oh look another line comment
+	// (two, in fact)
+	data-three="3"
+></div>
+
+<span /* inline */ /* another inline */ data-one="1"></span>
diff --git a/packages/svelte/tests/parser-modern/samples/comment-in-tag/output.json b/packages/svelte/tests/parser-modern/samples/comment-in-tag/output.json
new file mode 100644
index 0000000000..45a57d3049
--- /dev/null
+++ b/packages/svelte/tests/parser-modern/samples/comment-in-tag/output.json
@@ -0,0 +1,286 @@
+{
+	"css": null,
+	"js": [],
+	"start": 0,
+	"end": 261,
+	"type": "Root",
+	"fragment": {
+		"type": "Fragment",
+		"nodes": [
+			{
+				"type": "RegularElement",
+				"start": 0,
+				"end": 199,
+				"name": "div",
+				"name_loc": {
+					"start": {
+						"line": 1,
+						"column": 1,
+						"character": 1
+					},
+					"end": {
+						"line": 1,
+						"column": 4,
+						"character": 4
+					}
+				},
+				"attributes": [
+					{
+						"type": "Attribute",
+						"start": 6,
+						"end": 18,
+						"name": "data-one",
+						"name_loc": {
+							"start": {
+								"line": 2,
+								"column": 1,
+								"character": 6
+							},
+							"end": {
+								"line": 2,
+								"column": 9,
+								"character": 14
+							}
+						},
+						"value": [
+							{
+								"start": 16,
+								"end": 17,
+								"type": "Text",
+								"raw": "1",
+								"data": "1"
+							}
+						]
+					},
+					{
+						"type": "Attribute",
+						"start": 47,
+						"end": 59,
+						"name": "data-two",
+						"name_loc": {
+							"start": {
+								"line": 4,
+								"column": 1,
+								"character": 47
+							},
+							"end": {
+								"line": 4,
+								"column": 9,
+								"character": 55
+							}
+						},
+						"value": [
+							{
+								"start": 57,
+								"end": 58,
+								"type": "Text",
+								"raw": "2",
+								"data": "2"
+							}
+						]
+					},
+					{
+						"type": "Attribute",
+						"start": 177,
+						"end": 191,
+						"name": "data-three",
+						"name_loc": {
+							"start": {
+								"line": 19,
+								"column": 1,
+								"character": 177
+							},
+							"end": {
+								"line": 19,
+								"column": 11,
+								"character": 187
+							}
+						},
+						"value": [
+							{
+								"start": 189,
+								"end": 190,
+								"type": "Text",
+								"raw": "3",
+								"data": "3"
+							}
+						]
+					}
+				],
+				"fragment": {
+					"type": "Fragment",
+					"nodes": []
+				}
+			},
+			{
+				"type": "Text",
+				"start": 199,
+				"end": 201,
+				"raw": "\n\n",
+				"data": "\n\n"
+			},
+			{
+				"type": "RegularElement",
+				"start": 201,
+				"end": 261,
+				"name": "span",
+				"name_loc": {
+					"start": {
+						"line": 22,
+						"column": 1,
+						"character": 202
+					},
+					"end": {
+						"line": 22,
+						"column": 5,
+						"character": 206
+					}
+				},
+				"attributes": [
+					{
+						"type": "Attribute",
+						"start": 241,
+						"end": 253,
+						"name": "data-one",
+						"name_loc": {
+							"start": {
+								"line": 22,
+								"column": 40,
+								"character": 241
+							},
+							"end": {
+								"line": 22,
+								"column": 48,
+								"character": 249
+							}
+						},
+						"value": [
+							{
+								"start": 251,
+								"end": 252,
+								"type": "Text",
+								"raw": "1",
+								"data": "1"
+							}
+						]
+					}
+				],
+				"fragment": {
+					"type": "Fragment",
+					"nodes": []
+				}
+			}
+		]
+	},
+	"options": null,
+	"comments": [
+		{
+			"type": "Line",
+			"start": 20,
+			"end": 45,
+			"value": " this is a line comment",
+			"loc": {
+				"start": {
+					"line": 3,
+					"column": 1,
+					"character": 20
+				},
+				"end": {
+					"line": 3,
+					"column": 26,
+					"character": 45
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"start": 61,
+			"end": 123,
+			"value": " this is a\n\t\tm\n\t\tu\n\t\tl\n\t\tt\n\t\ti\n\t\tl\n\t\ti\n\t\tn\n\t\te\n\t\tcomment\n\t",
+			"loc": {
+				"start": {
+					"line": 5,
+					"column": 1,
+					"character": 61
+				},
+				"end": {
+					"line": 16,
+					"column": 3,
+					"character": 123
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"start": 125,
+			"end": 156,
+			"value": " oh look another line comment",
+			"loc": {
+				"start": {
+					"line": 17,
+					"column": 1,
+					"character": 125
+				},
+				"end": {
+					"line": 17,
+					"column": 32,
+					"character": 156
+				}
+			}
+		},
+		{
+			"type": "Line",
+			"start": 158,
+			"end": 175,
+			"value": " (two, in fact)",
+			"loc": {
+				"start": {
+					"line": 18,
+					"column": 1,
+					"character": 158
+				},
+				"end": {
+					"line": 18,
+					"column": 18,
+					"character": 175
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"start": 207,
+			"end": 219,
+			"value": " inline ",
+			"loc": {
+				"start": {
+					"line": 22,
+					"column": 6,
+					"character": 207
+				},
+				"end": {
+					"line": 22,
+					"column": 18,
+					"character": 219
+				}
+			}
+		},
+		{
+			"type": "Block",
+			"start": 220,
+			"end": 240,
+			"value": " another inline ",
+			"loc": {
+				"start": {
+					"line": 22,
+					"column": 19,
+					"character": 220
+				},
+				"end": {
+					"line": 22,
+					"column": 39,
+					"character": 240
+				}
+			}
+		}
+	]
+}
diff --git a/packages/svelte/tests/parser-modern/test.ts b/packages/svelte/tests/parser-modern/test.ts
index fb762e89e1..540a393c38 100644
--- a/packages/svelte/tests/parser-modern/test.ts
+++ b/packages/svelte/tests/parser-modern/test.ts
@@ -25,8 +25,6 @@ const { test, run } = suite<ParserTest>(async (config, cwd) => {
 		)
 	);
 
-	delete actual.comments;
-
 	// run `UPDATE_SNAPSHOTS=true pnpm test parser` to update parser tests
 	if (process.env.UPDATE_SNAPSHOTS) {
 		fs.writeFileSync(`${cwd}/output.json`, JSON.stringify(actual, null, '\t') + '\n');
@@ -34,6 +32,11 @@ const { test, run } = suite<ParserTest>(async (config, cwd) => {
 		fs.writeFileSync(`${cwd}/_actual.json`, JSON.stringify(actual, null, '\t'));
 
 		const expected = try_load_json(`${cwd}/output.json`);
+
+		if (!expected.comments) {
+			delete actual.comments;
+		}
+
 		assert.deepEqual(actual, expected);
 	}
 
@@ -50,7 +53,9 @@ const { test, run } = suite<ParserTest>(async (config, cwd) => {
 
 		fs.writeFileSync(`${cwd}/_actual.svelte`, printed.code);
 
-		delete reparsed.comments;
+		if (!actual.comments) {
+			delete reparsed.comments;
+		}
 
 		assert.deepEqual(clean(actual), clean(reparsed));
 	}
diff --git a/packages/svelte/tests/runtime-legacy/shared.ts b/packages/svelte/tests/runtime-legacy/shared.ts
index c5317f822e..454ae2f766 100644
--- a/packages/svelte/tests/runtime-legacy/shared.ts
+++ b/packages/svelte/tests/runtime-legacy/shared.ts
@@ -13,6 +13,7 @@ import type { CompileOptions } from '#compiler';
 import { suite_with_variants, type BaseTest } from '../suite.js';
 import { clear } from '../../src/internal/client/reactivity/batch.js';
 import { hydrating } from '../../src/internal/client/dom/hydration.js';
+import { ssr_context } from '../../src/internal/server/context.js';
 
 type Assert = typeof import('vitest').assert & {
 	htmlEqual(a: string, b: string, description?: string): void;
@@ -101,6 +102,7 @@ export interface RuntimeTest<Props extends Record<string, any> = Record<string,
 	expect_unhandled_rejections?: boolean;
 	withoutNormalizeHtml?: boolean | 'only-strip-comments';
 	recover?: boolean;
+	transformError?: (error: unknown) => unknown;
 }
 
 declare global {
@@ -358,12 +360,17 @@ async function run_test_variant(
 		let snapshot = undefined;
 
 		if (variant === 'hydrate' || variant === 'ssr' || variant === 'async-ssr') {
+			if (ssr_context !== null) {
+				throw new Error('ssr_context was not cleared');
+			}
+
 			config.before_test?.();
 			// ssr into target
 			const SsrSvelteComponent = (await import(`${cwd}/_output/server/main.svelte.js`)).default;
 			const render_result = render(SsrSvelteComponent, {
 				props: config.server_props ?? config.props ?? {},
-				idPrefix: config.id_prefix
+				idPrefix: config.id_prefix,
+				transformError: config.transformError
 			});
 			const rendered =
 				variant === 'async-ssr' || (variant === 'hydrate' && compileOptions.experimental?.async)
@@ -387,6 +394,10 @@ async function run_test_variant(
 					snapshot = config.snapshot(target);
 				}
 			}
+
+			if (ssr_context !== null) {
+				throw new Error('ssr_context was not cleared');
+			}
 		} else {
 			target.innerHTML = '';
 		}
@@ -462,7 +473,8 @@ async function run_test_variant(
 						target,
 						props,
 						intro: config.intro,
-						recover: config.recover ?? false
+						recover: config.recover ?? false,
+						transformError: config.transformError
 					});
 				}
 			} else {
diff --git a/packages/svelte/tests/runtime-runes/samples/async-boundary-nav-race/_config.js b/packages/svelte/tests/runtime-runes/samples/async-boundary-nav-race/_config.js
new file mode 100644
index 0000000000..940299618e
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-boundary-nav-race/_config.js
@@ -0,0 +1,82 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	html: `
+		<button>a</button>
+		<button>b</button>
+		<button>resolve a</button>
+		<button>resolve b</button>
+		<p>pending a</p>
+	`,
+	async test({ assert, target }) {
+		const [a, b, resolve_a, resolve_b] = target.querySelectorAll('button');
+
+		resolve_a.click();
+		await tick();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>a</button>
+				<button>b</button>
+				<button>resolve a</button>
+				<button>resolve b</button>
+				<p>page a</p>
+			`
+		);
+
+		b.click();
+		await tick();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>a</button>
+				<button>b</button>
+				<button>resolve a</button>
+				<button>resolve b</button>
+				<p>pending b</p>
+			`
+		);
+
+		a.click();
+		await tick();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>a</button>
+				<button>b</button>
+				<button>resolve a</button>
+				<button>resolve b</button>
+				<p>pending a</p>
+			`
+		);
+
+		resolve_b.click();
+		await tick();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>a</button>
+				<button>b</button>
+				<button>resolve a</button>
+				<button>resolve b</button>
+				<p>pending a</p>
+			`
+		);
+
+		resolve_a.click();
+		await tick();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>a</button>
+				<button>b</button>
+				<button>resolve a</button>
+				<button>resolve b</button>
+				<p>page a</p>
+			`
+		);
+
+		await new Promise((r) => setTimeout(r, 100));
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/async-boundary-nav-race/main.svelte b/packages/svelte/tests/runtime-runes/samples/async-boundary-nav-race/main.svelte
new file mode 100644
index 0000000000..a6554f5aa6
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-boundary-nav-race/main.svelte
@@ -0,0 +1,52 @@
+<script>
+	let page = $state('a');
+
+	/** @type {Array<() => void>} */
+	const a = [];
+	/** @type {Array<() => void>} */
+	const b = [];
+
+	function gate(next) {
+		const deferred = Promise.withResolvers();
+
+		if (next === 'a') a.push(deferred.resolve);
+		else b.push(deferred.resolve);
+
+		return deferred.promise;
+	}
+
+	function nav(next) {
+		page = next;
+	}
+
+	const to_render = $derived(page === 'a' ? snippet_a : snippet_b);
+</script>
+
+<button onclick={() => nav('a')}>a</button>
+<button onclick={() => nav('b')}>b</button>
+<button onclick={() => a.shift()?.()}>resolve a</button>
+<button onclick={() => b.shift()?.()}>resolve b</button>
+ 
+{#snippet snippet_a()}
+	<svelte:boundary>
+		{@const _a = await gate('a')}
+		<p>page a</p>
+
+		{#snippet pending()}
+			<p>pending a</p>
+		{/snippet}
+	</svelte:boundary>
+{/snippet}
+
+{#snippet snippet_b()}
+	<svelte:boundary>
+		{@const _b = await gate('b')}
+		<p>page b</p>
+
+		{#snippet pending()}
+			<p>pending b</p>
+		{/snippet}
+	</svelte:boundary>
+{/snippet}
+
+{@render to_render()} 
diff --git a/packages/svelte/tests/runtime-runes/samples/async-derived-title-update/_config.js b/packages/svelte/tests/runtime-runes/samples/async-derived-title-update/_config.js
new file mode 100644
index 0000000000..bda2f36efb
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-derived-title-update/_config.js
@@ -0,0 +1,12 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, target }) {
+		await tick();
+
+		const p = target.querySelector('p');
+		assert.equal(p?.innerHTML, 'hello');
+		assert.equal(window.document.title, 'hello');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/async-derived-title-update/main.svelte b/packages/svelte/tests/runtime-runes/samples/async-derived-title-update/main.svelte
new file mode 100644
index 0000000000..3af3c746f1
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-derived-title-update/main.svelte
@@ -0,0 +1,10 @@
+<script>
+	let promise = Promise.resolve('hello');
+	const value = $derived(await promise);
+</script>
+
+<svelte:head>
+	<title>{value}</title>
+</svelte:head>
+
+<p>{value}</p>
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/_config.js b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/_config.js
new file mode 100644
index 0000000000..202036421b
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/_config.js
@@ -0,0 +1,15 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['hydrate', 'async-server', 'client'],
+	ssrHtml: '<p>caught: error (hello)</p>',
+	transformError: () => {
+		return 'error';
+	},
+
+	async test({ assert, target }) {
+		await tick();
+		assert.htmlEqual(target.innerHTML, '<p>caught: error (hello)</p>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/child.svelte b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/child.svelte
new file mode 100644
index 0000000000..c6323d2925
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/child.svelte
@@ -0,0 +1,12 @@
+<script>
+	import { get } from "./main.svelte";
+
+    let { error } = $props();
+    const context = get()
+</script>
+
+{#if error}
+    <p>caught: {await error} ({context})</p>
+{:else}
+	{await Promise.reject('catch me')}
+{/if}
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/main.svelte b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/main.svelte
new file mode 100644
index 0000000000..a467f7500f
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-2/main.svelte
@@ -0,0 +1,19 @@
+<script module>
+	import { createContext } from "svelte";
+	import Child from "./child.svelte";
+
+	const [ get, set ] = createContext();
+	export {get};
+</script>
+
+<script>
+	set('hello');
+</script>
+
+<svelte:boundary>
+	{#snippet failed(error)}
+		<Child {error} />
+	{/snippet}
+
+	<Child />
+</svelte:boundary>
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/_config.js b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/_config.js
new file mode 100644
index 0000000000..641bbccd87
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/_config.js
@@ -0,0 +1,15 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['hydrate', 'async-server', 'client'],
+	ssrHtml: '<p>caught: error (hello)</p>',
+	transformError: () => {
+		return Promise.resolve('error');
+	},
+
+	async test({ assert, target }) {
+		await tick();
+		assert.htmlEqual(target.innerHTML, '<p>caught: error (hello)</p>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/child.svelte b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/child.svelte
new file mode 100644
index 0000000000..90d4c14cfc
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/child.svelte
@@ -0,0 +1,14 @@
+<script>
+	import { get } from "./main.svelte";
+
+    let { error } = $props();
+    const context = get()
+</script>
+
+{#if error}
+    <p>caught: {await error} ({context})</p>
+{:else}
+	{(() => {
+        throw 'catch me';
+    })()}
+{/if}
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/main.svelte b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/main.svelte
new file mode 100644
index 0000000000..a467f7500f
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary-3/main.svelte
@@ -0,0 +1,19 @@
+<script module>
+	import { createContext } from "svelte";
+	import Child from "./child.svelte";
+
+	const [ get, set ] = createContext();
+	export {get};
+</script>
+
+<script>
+	set('hello');
+</script>
+
+<svelte:boundary>
+	{#snippet failed(error)}
+		<Child {error} />
+	{/snippet}
+
+	<Child />
+</svelte:boundary>
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary/_config.js b/packages/svelte/tests/runtime-runes/samples/async-error-boundary/_config.js
new file mode 100644
index 0000000000..231a8c9d66
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary/_config.js
@@ -0,0 +1,16 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['hydrate', 'async-server', 'client'],
+	ssrHtml: '<p>caught: error</p>',
+	transformError: (error) => {
+		if (error !== 'catch me') throw 'wrong error object';
+		return 'error';
+	},
+
+	async test({ assert, target }) {
+		await tick();
+		assert.htmlEqual(target.innerHTML, '<p>caught: error</p>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/async-error-boundary/main.svelte b/packages/svelte/tests/runtime-runes/samples/async-error-boundary/main.svelte
new file mode 100644
index 0000000000..375ae273a9
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-error-boundary/main.svelte
@@ -0,0 +1,7 @@
+<svelte:boundary>
+	{#snippet failed(error)}
+		<p>caught: {error}</p>
+	{/snippet}
+
+	{await Promise.reject('catch me')}
+</svelte:boundary>
diff --git a/packages/svelte/tests/runtime-runes/samples/async-if-else/_config.js b/packages/svelte/tests/runtime-runes/samples/async-if-else/_config.js
new file mode 100644
index 0000000000..0a9c74fe65
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-if-else/_config.js
@@ -0,0 +1,17 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	mode: ['hydrate'],
+
+	async test({ assert, target }) {
+		const e = target.querySelector('#else-branch');
+
+		assert.equal(e?.isConnected, true);
+
+		await tick();
+
+		assert.equal(e?.isConnected, true);
+		assert.htmlEqual(target.innerHTML, '<p id="else-branch">else branch</p>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/async-if-else/main.svelte b/packages/svelte/tests/runtime-runes/samples/async-if-else/main.svelte
new file mode 100644
index 0000000000..e91cdd2a10
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/async-if-else/main.svelte
@@ -0,0 +1,5 @@
+{#if await false}
+	<p id="if-branch">if branch</p>
+{:else}
+	<p id="else-branch">{await 'else branch'}</p>
+{/if}
diff --git a/packages/svelte/tests/runtime-runes/samples/await-immediate-fulfilled/_config.js b/packages/svelte/tests/runtime-runes/samples/await-immediate-fulfilled/_config.js
new file mode 100644
index 0000000000..650bfe17a7
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/await-immediate-fulfilled/_config.js
@@ -0,0 +1,61 @@
+import { test } from '../../test';
+import { tick } from 'svelte';
+
+export default test({
+	async test({ assert, target }) {
+		const [resolveImmediate, resolveTimeout, rejectImmediate, rejectTimeout] =
+			target.querySelectorAll('button');
+
+		rejectTimeout.click();
+		await new Promise((resolve) => setTimeout(resolve, 1));
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>Resolve (immediate)</button>
+				<button>Resolve (timeout)</button>
+				<button>Reject (immediate)</button>
+				<button>Reject (timeout)</button>
+				<p> err [Yeah] </p>
+			`
+		);
+
+		resolveImmediate.click();
+		await tick();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>Resolve (immediate)</button>
+				<button>Resolve (timeout)</button>
+				<button>Reject (immediate)</button>
+				<button>Reject (timeout)</button>
+				<p> resolved [?] </p>
+			`
+		);
+
+		resolveTimeout.click();
+		await new Promise((resolve) => setTimeout(resolve, 1));
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>Resolve (immediate)</button>
+				<button>Resolve (timeout)</button>
+				<button>Reject (immediate)</button>
+				<button>Reject (timeout)</button>
+				<p> resolved [OK] </p>
+			`
+		);
+
+		rejectImmediate.click();
+		await tick();
+		assert.htmlEqual(
+			target.innerHTML,
+			`
+				<button>Resolve (immediate)</button>
+				<button>Resolve (timeout)</button>
+				<button>Reject (immediate)</button>
+				<button>Reject (timeout)</button>
+				<p> err [??] </p>
+			`
+		);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/await-immediate-fulfilled/main.svelte b/packages/svelte/tests/runtime-runes/samples/await-immediate-fulfilled/main.svelte
new file mode 100644
index 0000000000..d95b4f03a9
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/await-immediate-fulfilled/main.svelte
@@ -0,0 +1,34 @@
+<script>
+	let p = $state(null);
+</script>
+
+<button onclick={()=>{
+	p = new Promise((resolve, reject) => {
+		resolve("?");
+	});
+}}>Resolve (immediate)</button>
+<button onclick={()=>{
+	p = new Promise((resolve, reject) => {
+		setTimeout(() => resolve("OK"), 1);
+	});
+}}>Resolve (timeout)</button>
+<button onclick={()=>{
+	p = new Promise((resolve, reject) => {
+		reject("??");
+	});
+}}>Reject (immediate)</button>
+<button onclick={()=>{
+	p = new Promise((resolve, reject) => {
+		setTimeout(() => reject("Yeah"), 1);
+	});
+}}>Reject (timeout)</button>
+
+<p>
+	{#await p}
+		...
+	{:then v}
+		resolved [{v}]
+	{:catch err}
+		err [{err}]
+	{/await}
+</p>
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-name-shadowed/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-name-shadowed/_config.js
new file mode 100644
index 0000000000..8adc6cdae5
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/derived-name-shadowed/_config.js
@@ -0,0 +1,5 @@
+import { test } from '../../test';
+
+export default test({
+	html: `42`
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-name-shadowed/main.svelte b/packages/svelte/tests/runtime-runes/samples/derived-name-shadowed/main.svelte
new file mode 100644
index 0000000000..d780f80939
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/derived-name-shadowed/main.svelte
@@ -0,0 +1,8 @@
+<script module>
+	function foo() {
+		const foo = $derived(42);
+		return () => foo;
+	}
+</script>
+
+{foo()()}
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/_config.js
new file mode 100644
index 0000000000..4525e1ea81
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/_config.js
@@ -0,0 +1,11 @@
+import { test } from '../../test';
+
+export default test({
+	test_ssr({ assert, logs }) {
+		assert.deepEqual(logs, [0, 2, { count: 2 }, 0, 0, { local_count: 1 }]);
+	},
+
+	test({ assert, logs }) {
+		assert.deepEqual(logs, [0, 2, { count: 2 }, 0, 0, { local_count: 1 }]);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/main.svelte b/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/main.svelte
new file mode 100644
index 0000000000..b291707849
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/main.svelte
@@ -0,0 +1,21 @@
+<script>
+	import { reset, increment, get, count } from './state.svelte.js';
+
+	reset();
+	console.log(get());
+	increment();
+	console.log(get());
+	console.log({ count });
+
+	let local_count = 0;
+
+	let s = $state(0);
+	let d = $derived.by(() => {
+		local_count += 1;
+		return s * 2;
+	});
+
+	console.log(d);
+	console.log(d);
+	console.log({ local_count });
+</script>
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/state.svelte.js b/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/state.svelte.js
new file mode 100644
index 0000000000..df8f6f4795
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/derived-server-memoization/state.svelte.js
@@ -0,0 +1,20 @@
+let s = $state(0);
+let d = $derived.by(() => {
+	count += 1;
+	return s * 2;
+});
+
+export let count = 0;
+
+export function reset() {
+	count = 0;
+	s = 0;
+}
+
+export function increment() {
+	s += 1;
+}
+
+export function get() {
+	return d;
+}
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-update-server/_config.js b/packages/svelte/tests/runtime-runes/samples/derived-update-server/_config.js
new file mode 100644
index 0000000000..b819023a7c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/derived-update-server/_config.js
@@ -0,0 +1,6 @@
+import { test } from '../../test';
+
+export default test({
+	mode: ['async-server', 'server'],
+	html: '<p>postfix: 0, postfix_minus: 1, prefix: 1, prefix_minus: 0, count: 0</p><p>postfix_n: 0, postfix_minus_n: 1, prefix_n: 1, prefix_minus_n: 0, count_n: 0</p>'
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/derived-update-server/main.svelte b/packages/svelte/tests/runtime-runes/samples/derived-update-server/main.svelte
new file mode 100644
index 0000000000..04c5ee1b8c
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/derived-update-server/main.svelte
@@ -0,0 +1,17 @@
+<script>
+	let count = $derived(0);
+	let postfix = count++;
+	let postfix_minus = count--;
+	let prefix = ++count;
+	let prefix_minus = --count;
+
+	let count_n = $derived(0n);
+	let postfix_n = count_n++;
+	let postfix_minus_n = count_n--;
+	let prefix_n = ++count_n;
+	let prefix_minus_n = --count_n;
+</script>
+
+<p>postfix: {postfix}, postfix_minus: {postfix_minus}, prefix: {prefix}, prefix_minus: {prefix_minus}, count: {count}</p>
+<p>postfix_n: {postfix_n}, postfix_minus_n: {postfix_minus_n}, prefix_n: {prefix_n}, prefix_minus_n: {prefix_minus_n}, count_n: {count_n}</p>
+
diff --git a/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/Component.svelte b/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/Component.svelte
new file mode 100644
index 0000000000..57add17179
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/Component.svelte
@@ -0,0 +1,7 @@
+<div>Hello</div>
+
+<style>
+	div {
+		color: var(--color);
+	}
+</style>
diff --git a/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/_config.js b/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/_config.js
new file mode 100644
index 0000000000..3078392055
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/_config.js
@@ -0,0 +1,10 @@
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, target }) {
+		assert.htmlEqual(
+			target.innerHTML,
+			`<svelte-css-wrapper style="display: contents; --color: red;"><div class="svelte-lsmn3l">Hello</div></svelte-css-wrapper>`
+		);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/main.svelte b/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/main.svelte
new file mode 100644
index 0000000000..80aec26eef
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/dynamic-component-css-props/main.svelte
@@ -0,0 +1,6 @@
+<script>
+	import Component from './Component.svelte';
+	let Comp = Component;
+</script>
+
+<svelte:component this={Comp} --color="red" />
diff --git a/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/HelloWorld.svelte b/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/HelloWorld.svelte
new file mode 100644
index 0000000000..52ea02c559
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/HelloWorld.svelte
@@ -0,0 +1 @@
+<div>Hello world</div>
diff --git a/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/_config.js b/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/_config.js
new file mode 100644
index 0000000000..90dae38ad8
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/_config.js
@@ -0,0 +1,9 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, target }) {
+		await tick();
+		assert.htmlEqual(target.innerHTML, `<h1>Test</h1> <div>Hello world</div>`);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/main.svelte b/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/main.svelte
new file mode 100644
index 0000000000..8a410da609
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/dynamic-component-falsy-hydrate/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	import HelloWorld from './HelloWorld.svelte';
+
+	let Component = $state();
+
+	$effect.pre(() => {
+		Component = HelloWorld;
+	});
+</script>
+
+<h1>Test</h1>
+
+<Component />
diff --git a/packages/svelte/tests/runtime-runes/samples/each-key-volatile/_config.js b/packages/svelte/tests/runtime-runes/samples/each-key-volatile/_config.js
new file mode 100644
index 0000000000..87d4bf45c7
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/each-key-volatile/_config.js
@@ -0,0 +1,11 @@
+import { test } from '../../test';
+
+export default test({
+	compileOptions: {
+		dev: true
+	},
+
+	mode: ['client'],
+
+	error: 'each_key_volatile'
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/each-key-volatile/main.svelte b/packages/svelte/tests/runtime-runes/samples/each-key-volatile/main.svelte
new file mode 100644
index 0000000000..689c257cfa
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/each-key-volatile/main.svelte
@@ -0,0 +1,10 @@
+<script>
+	let things = $state([
+		{ group: 'a', id: 1 },
+		{ group: 'b', id: 2 }
+	]);
+</script>
+
+{#each things as thing ([thing.group, thing.id])}
+	<p>{thing.group}-{thing.id}</p>
+{/each}
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-26/_config.js b/packages/svelte/tests/runtime-runes/samples/error-boundary-26/_config.js
new file mode 100644
index 0000000000..3e9f30872d
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-26/_config.js
@@ -0,0 +1,15 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	html: '<p>caught: error</p>',
+	transformError: (error) => {
+		if (error !== 'catch me') throw 'wrong error object';
+		return 'error';
+	},
+
+	async test({ assert, target }) {
+		await tick();
+		assert.htmlEqual(target.innerHTML, '<p>caught: error</p>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-26/main.svelte b/packages/svelte/tests/runtime-runes/samples/error-boundary-26/main.svelte
new file mode 100644
index 0000000000..88d549f6d5
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-26/main.svelte
@@ -0,0 +1,7 @@
+<svelte:boundary>
+	{#snippet failed(error)}
+		<p>caught: {error}</p>
+	{/snippet}
+
+	{(() => {throw 'catch me'})()}
+</svelte:boundary>
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-27/_config.js b/packages/svelte/tests/runtime-runes/samples/error-boundary-27/_config.js
new file mode 100644
index 0000000000..df0d48b76a
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-27/_config.js
@@ -0,0 +1,14 @@
+import { tick } from 'svelte';
+import { test } from '../../test';
+
+export default test({
+	html: '<p>caught: error (hello)</p>',
+	transformError: () => {
+		return 'error';
+	},
+
+	async test({ assert, target }) {
+		await tick();
+		assert.htmlEqual(target.innerHTML, '<p>caught: error (hello)</p>');
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-27/child.svelte b/packages/svelte/tests/runtime-runes/samples/error-boundary-27/child.svelte
new file mode 100644
index 0000000000..5b680f1d08
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-27/child.svelte
@@ -0,0 +1,12 @@
+<script>
+	import { get } from "./main.svelte";
+
+    let { error } = $props();
+    const context = get()
+</script>
+
+{#if error}
+    <p>caught: {error} ({context})</p>
+{:else}
+	{(() => {throw 'catch me'})()}
+{/if}
\ No newline at end of file
diff --git a/packages/svelte/tests/runtime-runes/samples/error-boundary-27/main.svelte b/packages/svelte/tests/runtime-runes/samples/error-boundary-27/main.svelte
new file mode 100644
index 0000000000..a467f7500f
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/error-boundary-27/main.svelte
@@ -0,0 +1,19 @@
+<script module>
+	import { createContext } from "svelte";
+	import Child from "./child.svelte";
+
+	const [ get, set ] = createContext();
+	export {get};
+</script>
+
+<script>
+	set('hello');
+</script>
+
+<svelte:boundary>
+	{#snippet failed(error)}
+		<Child {error} />
+	{/snippet}
+
+	<Child />
+</svelte:boundary>
diff --git a/packages/svelte/tests/runtime-runes/samples/function-parameter-shadowing/_config.js b/packages/svelte/tests/runtime-runes/samples/function-parameter-shadowing/_config.js
new file mode 100644
index 0000000000..c35d4d7ff8
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/function-parameter-shadowing/_config.js
@@ -0,0 +1,7 @@
+import { test } from '../../test';
+
+export default test({
+	test({ assert, logs }) {
+		assert.deepEqual(logs, [42, 43]);
+	}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/function-parameter-shadowing/main.svelte b/packages/svelte/tests/runtime-runes/samples/function-parameter-shadowing/main.svelte
new file mode 100644
index 0000000000..2e7aef1742
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/function-parameter-shadowing/main.svelte
@@ -0,0 +1,12 @@
+<script>
+	let value = $state(42);
+
+	function shadow(output = value) {
+		const value = 1337;
+		return output;
+	}
+
+	console.log(shadow());
+	value += 1;
+	console.log(shadow());
+</script>
diff --git a/packages/svelte/tests/runtime-runes/samples/set-text-stable-coercion/_config.js b/packages/svelte/tests/runtime-runes/samples/set-text-stable-coercion/_config.js
new file mode 100644
index 0000000000..01ef02510a
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/set-text-stable-coercion/_config.js
@@ -0,0 +1,6 @@
+import { test } from '../../test';
+
+export default test({
+	html: 'toString <p>toString</p> <p>[toString]</p> toString',
+	async test() {}
+});
diff --git a/packages/svelte/tests/runtime-runes/samples/set-text-stable-coercion/main.svelte b/packages/svelte/tests/runtime-runes/samples/set-text-stable-coercion/main.svelte
new file mode 100644
index 0000000000..601e7ce9fb
--- /dev/null
+++ b/packages/svelte/tests/runtime-runes/samples/set-text-stable-coercion/main.svelte
@@ -0,0 +1,22 @@
+<script>
+	class Widget {
+		toString() { return "toString" }
+		valueOf() { return "valueOf" }
+	}
+
+	const value = new Widget();
+</script>
+
+<!-- case 1 -->
+{value}
+
+<!-- case 2 -->
+<p>{value}</p>
+
+<!-- case 3 -->
+<p>[{value}]</p>
+
+<!-- case 4 -->
+{#if 1}
+	{value}
+{/if}
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/_config.js
new file mode 100644
index 0000000000..6989172de4
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/_config.js
@@ -0,0 +1,10 @@
+import { test } from '../../test';
+
+export default test({
+	transformError: (error) => {
+		if (/** @type {Error} */ (error).message !== 'you are not supposed to see this message') {
+			return 'wrong object passed to transformError';
+		}
+		return 'component error';
+	}
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/_expected.html b/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/_expected.html
new file mode 100644
index 0000000000..da06ee2b39
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/_expected.html
@@ -0,0 +1 @@
+<p>caught: component error</p>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/main.svelte
new file mode 100644
index 0000000000..29086b359d
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-failed-prop/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	function throws() {
+		throw new Error('you are not supposed to see this message');
+	}
+</script>
+
+{#snippet failed(error)}
+	<p>caught: {error}</p>
+{/snippet}
+
+<svelte:boundary {failed}>
+	<p>{throws()}</p>
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/_config.js
new file mode 100644
index 0000000000..2e3ffc6ab3
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/_config.js
@@ -0,0 +1,8 @@
+import { test } from '../../test';
+
+export default test({
+	props: {
+		query: '--!><img src=x onerror=alert(1)><!--'
+	},
+	transformError: (error) => ({ message: /** @type {Error} */ (error).message })
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/_expected.html b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/_expected.html
new file mode 100644
index 0000000000..ab5e48766f
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/_expected.html
@@ -0,0 +1 @@
+<p class="error">--!>&lt;img src=x onerror=alert(1)>&lt;!--</p>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/main.svelte
new file mode 100644
index 0000000000..dd2955ecc4
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-close-bang-escape/main.svelte
@@ -0,0 +1,15 @@
+<script>
+	let { query } = $props();
+
+	function search(q) {
+		throw new Error(q);
+	}
+</script>
+
+<svelte:boundary>
+	<p>{search(query)}</p>
+
+	{#snippet failed(error)}
+		<p class="error">{error.message}</p>
+	{/snippet}
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/_config.js
new file mode 100644
index 0000000000..1644604a7b
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/_config.js
@@ -0,0 +1,8 @@
+import { test } from '../../test';
+
+export default test({
+	props: {
+		query: '--><img src=x onerror=alert(1)><!--'
+	},
+	transformError: (error) => ({ message: /** @type {Error} */ (error).message })
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/_expected.html b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/_expected.html
new file mode 100644
index 0000000000..d718344e5c
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/_expected.html
@@ -0,0 +1 @@
+<p class="error">-->&lt;img src=x onerror=alert(1)>&lt;!--</p>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/main.svelte
new file mode 100644
index 0000000000..dd2955ecc4
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-escape/main.svelte
@@ -0,0 +1,15 @@
+<script>
+	let { query } = $props();
+
+	function search(q) {
+		throw new Error(q);
+	}
+</script>
+
+<svelte:boundary>
+	<p>{search(query)}</p>
+
+	{#snippet failed(error)}
+		<p class="error">{error.message}</p>
+	{/snippet}
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/_config.js
new file mode 100644
index 0000000000..a4f74e8b21
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/_config.js
@@ -0,0 +1,8 @@
+import { test } from '../../test';
+
+export default test({
+	props: {
+		query: '<!--<script>alert(1)</script>'
+	},
+	transformError: (error) => ({ message: /** @type {Error} */ (error).message })
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/_expected.html b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/_expected.html
new file mode 100644
index 0000000000..1bde51be0a
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/_expected.html
@@ -0,0 +1 @@
+<p class="error">&lt;!--&lt;script&gt;alert(1)&lt;/script&gt;</p>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/main.svelte
new file mode 100644
index 0000000000..dd2955ecc4
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-open-escape/main.svelte
@@ -0,0 +1,15 @@
+<script>
+	let { query } = $props();
+
+	function search(q) {
+		throw new Error(q);
+	}
+</script>
+
+<svelte:boundary>
+	<p>{search(query)}</p>
+
+	{#snippet failed(error)}
+		<p class="error">{error.message}</p>
+	{/snippet}
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/_config.js
new file mode 100644
index 0000000000..938edf4ec5
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/_config.js
@@ -0,0 +1,8 @@
+import { test } from '../../test';
+
+export default test({
+	props: {
+		query: '<!--><!--->-->'
+	},
+	transformError: (error) => ({ message: /** @type {Error} */ (error).message })
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/_expected.html b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/_expected.html
new file mode 100644
index 0000000000..7d338ce71b
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/_expected.html
@@ -0,0 +1 @@
+<p class="error">&lt;!--&gt;&lt;!---&gt;--&gt;</p>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/main.svelte
new file mode 100644
index 0000000000..dd2955ecc4
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-html-comment-overlap-escape/main.svelte
@@ -0,0 +1,15 @@
+<script>
+	let { query } = $props();
+
+	function search(q) {
+		throw new Error(q);
+	}
+</script>
+
+<svelte:boundary>
+	<p>{search(query)}</p>
+
+	{#snippet failed(error)}
+		<p class="error">{error.message}</p>
+	{/snippet}
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-failed-snippet/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-failed-snippet/_config.js
new file mode 100644
index 0000000000..ae78cb4825
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-failed-snippet/_config.js
@@ -0,0 +1,8 @@
+import { test } from '../../test';
+
+export default test({
+	// transformError transforms the error, but there's no failed snippet.
+	// The error should still propagate because there's nothing to render instead.
+	transformError: () => 'you will not see me',
+	error: 'component error'
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-failed-snippet/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-failed-snippet/main.svelte
new file mode 100644
index 0000000000..98275badb3
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-failed-snippet/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	function throws() {
+		throw new Error('component error');
+	}
+</script>
+
+<svelte:boundary onerror={() => {}}>
+	<p>{throws()}</p>
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-onerror/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-onerror/_config.js
new file mode 100644
index 0000000000..ecc506203f
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-onerror/_config.js
@@ -0,0 +1,6 @@
+import { test } from '../../test';
+
+export default test({
+	// No transformError - by default the server throws, so the error should propagate.
+	error: 'component error'
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-onerror/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-onerror/main.svelte
new file mode 100644
index 0000000000..7dd2cf310e
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-no-onerror/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	function throws() {
+		throw new Error('component error');
+	}
+</script>
+
+<svelte:boundary>
+	<p>{throws()}</p>
+
+	{#snippet failed(error)}
+		<p>caught: {error}</p>
+	{/snippet}
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/_config.js b/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/_config.js
new file mode 100644
index 0000000000..e1cb96759f
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/_config.js
@@ -0,0 +1,11 @@
+import { test } from '../../test';
+
+export default test({
+	// boundary with failed snippet exists, so transformError should transform the error
+	transformError: (error) => {
+		if (/** @type {Error} */ (error).message !== 'you are not supposed to see this message') {
+			return 'wrong object passed to transformError';
+		}
+		return 'component error';
+	}
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/_expected.html b/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/_expected.html
new file mode 100644
index 0000000000..293de47610
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/_expected.html
@@ -0,0 +1 @@
+<p>caught: component error</p>
\ No newline at end of file
diff --git a/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/main.svelte b/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/main.svelte
new file mode 100644
index 0000000000..a2d1435e76
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/boundary-error-with-onerror/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	function throws() {
+		throw new Error('you are not supposed to see this message');
+	}
+</script>
+
+<svelte:boundary>
+	<p>{throws()}</p>
+
+	{#snippet failed(error)}
+		<p>caught: {error}</p>
+	{/snippet}
+</svelte:boundary>
diff --git a/packages/svelte/tests/server-side-rendering/samples/contenteditable-bindings-escaped/_expected.html b/packages/svelte/tests/server-side-rendering/samples/contenteditable-bindings-escaped/_expected.html
new file mode 100644
index 0000000000..648895aca6
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/contenteditable-bindings-escaped/_expected.html
@@ -0,0 +1 @@
+<!--[--><div contenteditable="">&lt;script>alert('pwnd')&lt;/script></div> <div contenteditable="">&lt;script>alert('pwnd')&lt;/script></div> <div contenteditable=""><script>alert('pwnd')</script></div><!--]-->
\ No newline at end of file
diff --git a/packages/svelte/tests/server-side-rendering/samples/contenteditable-bindings-escaped/main.svelte b/packages/svelte/tests/server-side-rendering/samples/contenteditable-bindings-escaped/main.svelte
new file mode 100644
index 0000000000..e5ccb4b6db
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/contenteditable-bindings-escaped/main.svelte
@@ -0,0 +1,7 @@
+<script>
+	let data = $state("<scri"+"pt>alert('pwnd')</scr"+"ipt>");
+</script>
+
+<div contenteditable bind:innerText={data}></div>
+<div contenteditable bind:textContent={data}></div>
+<div contenteditable bind:innerHTML={data}></div>
diff --git a/packages/svelte/tests/server-side-rendering/samples/dynamic-element-xss-prevention/_config.js b/packages/svelte/tests/server-side-rendering/samples/dynamic-element-xss-prevention/_config.js
new file mode 100644
index 0000000000..ddbe9a4b16
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/dynamic-element-xss-prevention/_config.js
@@ -0,0 +1,8 @@
+import { test } from '../../test';
+
+export default test({
+	props: {
+		tag: 'svg onload=alert(1)'
+	},
+	error: 'dynamic_element_invalid_tag'
+});
diff --git a/packages/svelte/tests/server-side-rendering/samples/dynamic-element-xss-prevention/main.svelte b/packages/svelte/tests/server-side-rendering/samples/dynamic-element-xss-prevention/main.svelte
new file mode 100644
index 0000000000..94ad88cf0a
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/dynamic-element-xss-prevention/main.svelte
@@ -0,0 +1,5 @@
+<script>
+	let { tag } = $props();
+</script>
+
+<svelte:element this={tag}>ok</svelte:element>
diff --git a/packages/svelte/tests/server-side-rendering/samples/option-body-escaped/_expected.html b/packages/svelte/tests/server-side-rendering/samples/option-body-escaped/_expected.html
new file mode 100644
index 0000000000..0802f01083
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/option-body-escaped/_expected.html
@@ -0,0 +1 @@
+<!--[--><select><option>a&lt;/option>&lt;script>alert("pwnd")&lt;/script>&lt;option>puppa</option><option>selected: a&lt;/option>&lt;script>alert("pwnd")&lt;/script>&lt;option>puppa</option></select><!--]-->
\ No newline at end of file
diff --git a/packages/svelte/tests/server-side-rendering/samples/option-body-escaped/main.svelte b/packages/svelte/tests/server-side-rendering/samples/option-body-escaped/main.svelte
new file mode 100644
index 0000000000..a2f96383d1
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/option-body-escaped/main.svelte
@@ -0,0 +1,9 @@
+<script>
+	let {
+    selectedBook = "a</option><sc" + "ript>alert(\"pwnd\")</sc" + "ript><option>puppa"
+  } = $props();
+</script>
+<select>
+  <option>{selectedBook}</option>
+  <option>selected: {selectedBook}</option>
+</select>
diff --git a/packages/svelte/tests/server-side-rendering/samples/spread-attributes-event-handler-xss/_expected.html b/packages/svelte/tests/server-side-rendering/samples/spread-attributes-event-handler-xss/_expected.html
new file mode 100644
index 0000000000..2a982292e5
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/spread-attributes-event-handler-xss/_expected.html
@@ -0,0 +1,3 @@
+<div id="profile-123" class="card">content</div>
+
+<img src="x" alt="photo" />
diff --git a/packages/svelte/tests/server-side-rendering/samples/spread-attributes-event-handler-xss/main.svelte b/packages/svelte/tests/server-side-rendering/samples/spread-attributes-event-handler-xss/main.svelte
new file mode 100644
index 0000000000..2a8c17f048
--- /dev/null
+++ b/packages/svelte/tests/server-side-rendering/samples/spread-attributes-event-handler-xss/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	const userdata = {
+		id: 'profile-123',
+		class: 'card',
+		onclick: 'alert(1)',
+		onerror: 'alert(1)',
+		onfocus: 'alert(1)',
+		onmouseover: 'alert(1)'
+	};
+</script>
+
+<div {...userdata}>content</div>
+<img src="x" alt="photo" {...{ onerror: 'alert(1)', onload: 'alert(1)' }} />
diff --git a/packages/svelte/tests/server-side-rendering/test.ts b/packages/svelte/tests/server-side-rendering/test.ts
index ca98fdd9aa..2dcaa85708 100644
--- a/packages/svelte/tests/server-side-rendering/test.ts
+++ b/packages/svelte/tests/server-side-rendering/test.ts
@@ -24,6 +24,7 @@ interface SSRTest extends BaseTest {
 	error?: string;
 	csp?: { nonce: string } | { hash: true };
 	script_hashes?: string[];
+	transformError?: (error: unknown) => unknown;
 }
 
 // TODO remove this shim when we can
@@ -84,7 +85,8 @@ const { test, run } = suite_with_variants<SSRTest, 'sync' | 'async', CompileOpti
 			const render_result = render(Component, {
 				props: config.props || {},
 				idPrefix: config.id_prefix,
-				csp: config.csp
+				csp: config.csp,
+				transformError: config.transformError
 			});
 			rendered = is_async ? await render_result : render_result;
 			// we need to access these inside the try-catch otherwise errors in the script tag are not caught
diff --git a/packages/svelte/tests/snapshot/samples/async-if-chain/_expected/server/index.svelte.js b/packages/svelte/tests/snapshot/samples/async-if-chain/_expected/server/index.svelte.js
index 91315edb94..1b1ab51d6f 100644
--- a/packages/svelte/tests/snapshot/samples/async-if-chain/_expected/server/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/async-if-chain/_expected/server/index.svelte.js
@@ -8,7 +8,7 @@ export default function Async_if_chain($$renderer) {
 
 	let foo = true;
 	var blocking;
-	var $$promises = $$renderer.run([async () => blocking = await foo]);
+	var $$promises = $$renderer.run([async () => blocking = await $.async_derived(() => foo)]);
 
 	$$renderer.async_block([$$promises[0]], ($$renderer) => {
 		if (foo) {
@@ -94,10 +94,10 @@ export default function Async_if_chain($$renderer) {
 	$$renderer.push(`<!--]--> `);
 
 	$$renderer.async_block([$$promises[0]], ($$renderer) => {
-		if (blocking > 10) {
+		if (blocking() > 10) {
 			$$renderer.push('<!--[-->');
 			$$renderer.push(`foo`);
-		} else if (blocking > 5) {
+		} else if (blocking() > 5) {
 			$$renderer.push('<!--[1-->');
 			$$renderer.push(`bar`);
 		} else {
diff --git a/packages/svelte/tests/snapshot/samples/async-in-derived/_expected/server/index.svelte.js b/packages/svelte/tests/snapshot/samples/async-in-derived/_expected/server/index.svelte.js
index 58358b3ded..3af9f504ec 100644
--- a/packages/svelte/tests/snapshot/samples/async-in-derived/_expected/server/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/async-in-derived/_expected/server/index.svelte.js
@@ -6,15 +6,15 @@ export default function Async_in_derived($$renderer, $$props) {
 		var yes1, yes2, no1, no2;
 
 		var $$promises = $$renderer.run([
-			async () => yes1 = await 1,
-			async () => yes2 = foo(await 1),
-			() => no1 = (async () => {
+			async () => yes1 = await $.async_derived(() => 1),
+			async () => yes2 = await $.async_derived(async () => foo(await 1)),
+			() => no1 = $.derived(async () => {
 				return await 1;
-			})(),
+			}),
 
-			() => no2 = async () => {
+			() => no2 = $.derived(() => async () => {
 				return await 1;
-			}
+			})
 		]);
 
 		if (true) {
diff --git a/packages/svelte/tests/snapshot/samples/await-block-scope/_expected/server/index.svelte.js b/packages/svelte/tests/snapshot/samples/await-block-scope/_expected/server/index.svelte.js
index e9bf215dcd..a41b58051c 100644
--- a/packages/svelte/tests/snapshot/samples/await-block-scope/_expected/server/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/await-block-scope/_expected/server/index.svelte.js
@@ -2,13 +2,13 @@ import * as $ from 'svelte/internal/server';
 
 export default function Await_block_scope($$renderer) {
 	let counter = { count: 0 };
-	const promise = Promise.resolve(counter);
+	const promise = $.derived(() => Promise.resolve(counter));
 
 	function increment() {
 		counter.count += 1;
 	}
 
 	$$renderer.push(`<button>clicks: ${$.escape(counter.count)}</button> `);
-	$.await($$renderer, promise, () => {}, (counter) => {});
+	$.await($$renderer, promise(), () => {}, (counter) => {});
 	$$renderer.push(`<!--]--> ${$.escape(counter.count)}`);
 }
\ No newline at end of file
diff --git a/packages/svelte/tests/snapshot/samples/select-with-rich-content/_expected/server/index.svelte.js b/packages/svelte/tests/snapshot/samples/select-with-rich-content/_expected/server/index.svelte.js
index acf873ac09..a50200a769 100644
--- a/packages/svelte/tests/snapshot/samples/select-with-rich-content/_expected/server/index.svelte.js
+++ b/packages/svelte/tests/snapshot/samples/select-with-rich-content/_expected/server/index.svelte.js
@@ -164,7 +164,8 @@ export default function Select_with_rich_content($$renderer) {
 		$$renderer.push('<!--[!-->');
 	}
 
-	$$renderer.push(`<!--]--></select> <select><!--[-->`);
+	$$renderer.push(`<!--]--></select> <select>`);
+	$$renderer.push(`<!--[-->`);
 
 	{
 		$$renderer.option({}, ($$renderer) => {
@@ -172,7 +173,9 @@ export default function Select_with_rich_content($$renderer) {
 		});
 	}
 
-	$$renderer.push(`<!--]--></select> <select><!--[-->`);
+	$$renderer.push(`<!--]-->`);
+	$$renderer.push(`</select> <select>`);
+	$$renderer.push(`<!--[-->`);
 
 	{
 		$$renderer.option(
@@ -188,7 +191,8 @@ export default function Select_with_rich_content($$renderer) {
 		);
 	}
 
-	$$renderer.push(`<!--]--></select> <select>`);
+	$$renderer.push(`<!--]-->`);
+	$$renderer.push(`</select> <select>`);
 	Option($$renderer, {});
 	$$renderer.push(`<!----><!></select>  <select>`);
 	option_snippet($$renderer);
diff --git a/packages/svelte/types/index.d.ts b/packages/svelte/types/index.d.ts
index e7aa5395b8..31ef9110df 100644
--- a/packages/svelte/types/index.d.ts
+++ b/packages/svelte/types/index.d.ts
@@ -20,6 +20,7 @@ declare module 'svelte' {
 		sync?: boolean;
 		idPrefix?: string;
 		$$inline?: boolean;
+		transformError?: (error: unknown) => unknown;
 	}
 
 	/**
@@ -337,6 +338,11 @@ declare module 'svelte' {
 		 * @default true
 		 */
 		intro?: boolean;
+		/**
+		 * A function that transforms errors caught by error boundaries before they are passed to the `failed` snippet.
+		 * Defaults to the identity function.
+		 */
+		transformError?: (error: unknown) => unknown | Promise<unknown>;
 	} & ({} extends Props
 		? {
 				/**
@@ -542,6 +548,7 @@ declare module 'svelte' {
 		context?: Map<any, any>;
 		intro?: boolean;
 		recover?: boolean;
+		transformError?: (error: unknown) => unknown;
 	} : {
 		target: Document | Element | ShadowRoot;
 		props: Props;
@@ -549,6 +556,7 @@ declare module 'svelte' {
 		context?: Map<any, any>;
 		intro?: boolean;
 		recover?: boolean;
+		transformError?: (error: unknown) => unknown;
 	}): Exports;
 	/**
 	 * Unmounts a component that was previously mounted using `mount` or `hydrate`.
@@ -2567,6 +2575,7 @@ declare module 'svelte/server' {
 						context?: Map<any, any>;
 						idPrefix?: string;
 						csp?: Csp;
+						transformError?: (error: unknown) => unknown | Promise<unknown>;
 					}
 				]
 			: [
@@ -2576,6 +2585,7 @@ declare module 'svelte/server' {
 						context?: Map<any, any>;
 						idPrefix?: string;
 						csp?: Csp;
+						transformError?: (error: unknown) => unknown | Promise<unknown>;
 					}
 				]
 	): RenderOutput;
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 1d3427fae0..e5d857ee81 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -15,8 +15,8 @@ importers:
         specifier: ^10.0.0
         version: 10.0.1(eslint@10.0.0)
       '@sveltejs/eslint-config':
-        specifier: ^8.3.5
-        version: 8.3.5(@stylistic/eslint-plugin-js@1.8.0(eslint@10.0.0))(eslint-config-prettier@9.1.0(eslint@10.0.0))(eslint-plugin-n@17.16.1(eslint@10.0.0)(typescript@5.5.4))(eslint-plugin-svelte@3.15.0(eslint@10.0.0)(svelte@packages+svelte))(eslint@10.0.0)(typescript-eslint@8.55.0(eslint@10.0.0)(typescript@5.5.4))(typescript@5.5.4)
+        specifier: ^9.0.0
+        version: 9.0.0(@eslint/js@10.0.1(eslint@10.0.0))(@stylistic/eslint-plugin-js@1.8.0(eslint@10.0.0))(eslint-config-prettier@9.1.0(eslint@10.0.0))(eslint-plugin-n@17.24.0(eslint@10.0.0)(typescript@5.5.4))(eslint-plugin-svelte@3.15.0(eslint@10.0.0)(svelte@packages+svelte))(eslint@10.0.0)(typescript-eslint@8.56.0(eslint@10.0.0)(typescript@5.5.4))(typescript@5.5.4)
       '@svitejs/changesets-changelog-github-compact':
         specifier: ^1.1.0
         version: 1.1.0
@@ -57,8 +57,8 @@ importers:
         specifier: ^5.5.4
         version: 5.5.4
       typescript-eslint:
-        specifier: ^8.55.0
-        version: 8.55.0(eslint@10.0.0)(typescript@5.5.4)
+        specifier: ^8.56.0
+        version: 8.56.0(eslint@10.0.0)(typescript@5.5.4)
       v8-natives:
         specifier: ^1.2.5
         version: 1.2.5
@@ -87,7 +87,7 @@ importers:
         specifier: ^8.12.1
         version: 8.15.0
       aria-query:
-        specifier: ^5.3.1
+        specifier: 5.3.1
         version: 5.3.1
       axobject-query:
         specifier: ^4.1.0
@@ -96,8 +96,8 @@ importers:
         specifier: ^2.1.1
         version: 2.1.1
       devalue:
-        specifier: ^5.6.2
-        version: 5.6.2
+        specifier: ^5.6.3
+        version: 5.6.3
       esm-env:
         specifier: ^1.2.1
         version: 1.2.1
@@ -125,16 +125,16 @@ importers:
         version: 1.58.0
       '@rollup/plugin-commonjs':
         specifier: ^28.0.1
-        version: 28.0.1(rollup@4.52.5)
+        version: 28.0.1(rollup@4.59.0)
       '@rollup/plugin-node-resolve':
         specifier: ^15.3.0
-        version: 15.3.0(rollup@4.52.5)
+        version: 15.3.0(rollup@4.59.0)
       '@rollup/plugin-terser':
         specifier: ^0.4.4
-        version: 0.4.4(rollup@4.52.5)
+        version: 0.4.4(rollup@4.59.0)
       '@rollup/plugin-virtual':
         specifier: ^3.0.2
-        version: 3.0.2(rollup@4.52.5)
+        version: 3.0.2(rollup@4.59.0)
       '@types/aria-query':
         specifier: ^5.0.4
         version: 5.0.4
@@ -148,8 +148,8 @@ importers:
         specifier: ^0.25.10
         version: 0.25.11
       rollup:
-        specifier: ^4.22.4
-        version: 4.52.5
+        specifier: ^4.59.0
+        version: 4.59.0
       source-map:
         specifier: ^0.7.4
         version: 0.7.4
@@ -755,113 +755,128 @@ packages:
       rollup:
         optional: true
 
-  '@rollup/rollup-android-arm-eabi@4.52.5':
-    resolution: {integrity: sha512-8c1vW4ocv3UOMp9K+gToY5zL2XiiVw3k7f1ksf4yO1FlDFQ1C2u72iACFnSOceJFsWskc2WZNqeRhFRPzv+wtQ==}
+  '@rollup/rollup-android-arm-eabi@4.59.0':
+    resolution: {integrity: sha512-upnNBkA6ZH2VKGcBj9Fyl9IGNPULcjXRlg0LLeaioQWueH30p6IXtJEbKAgvyv+mJaMxSm1l6xwDXYjpEMiLMg==}
     cpu: [arm]
     os: [android]
 
-  '@rollup/rollup-android-arm64@4.52.5':
-    resolution: {integrity: sha512-mQGfsIEFcu21mvqkEKKu2dYmtuSZOBMmAl5CFlPGLY94Vlcm+zWApK7F/eocsNzp8tKmbeBP8yXyAbx0XHsFNA==}
+  '@rollup/rollup-android-arm64@4.59.0':
+    resolution: {integrity: sha512-hZ+Zxj3SySm4A/DylsDKZAeVg0mvi++0PYVceVyX7hemkw7OreKdCvW2oQ3T1FMZvCaQXqOTHb8qmBShoqk69Q==}
     cpu: [arm64]
     os: [android]
 
-  '@rollup/rollup-darwin-arm64@4.52.5':
-    resolution: {integrity: sha512-takF3CR71mCAGA+v794QUZ0b6ZSrgJkArC+gUiG6LB6TQty9T0Mqh3m2ImRBOxS2IeYBo4lKWIieSvnEk2OQWA==}
+  '@rollup/rollup-darwin-arm64@4.59.0':
+    resolution: {integrity: sha512-W2Psnbh1J8ZJw0xKAd8zdNgF9HRLkdWwwdWqubSVk0pUuQkoHnv7rx4GiF9rT4t5DIZGAsConRE3AxCdJ4m8rg==}
     cpu: [arm64]
     os: [darwin]
 
-  '@rollup/rollup-darwin-x64@4.52.5':
-    resolution: {integrity: sha512-W901Pla8Ya95WpxDn//VF9K9u2JbocwV/v75TE0YIHNTbhqUTv9w4VuQ9MaWlNOkkEfFwkdNhXgcLqPSmHy0fA==}
+  '@rollup/rollup-darwin-x64@4.59.0':
+    resolution: {integrity: sha512-ZW2KkwlS4lwTv7ZVsYDiARfFCnSGhzYPdiOU4IM2fDbL+QGlyAbjgSFuqNRbSthybLbIJ915UtZBtmuLrQAT/w==}
     cpu: [x64]
     os: [darwin]
 
-  '@rollup/rollup-freebsd-arm64@4.52.5':
-    resolution: {integrity: sha512-QofO7i7JycsYOWxe0GFqhLmF6l1TqBswJMvICnRUjqCx8b47MTo46W8AoeQwiokAx3zVryVnxtBMcGcnX12LvA==}
+  '@rollup/rollup-freebsd-arm64@4.59.0':
+    resolution: {integrity: sha512-EsKaJ5ytAu9jI3lonzn3BgG8iRBjV4LxZexygcQbpiU0wU0ATxhNVEpXKfUa0pS05gTcSDMKpn3Sx+QB9RlTTA==}
     cpu: [arm64]
     os: [freebsd]
 
-  '@rollup/rollup-freebsd-x64@4.52.5':
-    resolution: {integrity: sha512-jr21b/99ew8ujZubPo9skbrItHEIE50WdV86cdSoRkKtmWa+DDr6fu2c/xyRT0F/WazZpam6kk7IHBerSL7LDQ==}
+  '@rollup/rollup-freebsd-x64@4.59.0':
+    resolution: {integrity: sha512-d3DuZi2KzTMjImrxoHIAODUZYoUUMsuUiY4SRRcJy6NJoZ6iIqWnJu9IScV9jXysyGMVuW+KNzZvBLOcpdl3Vg==}
     cpu: [x64]
     os: [freebsd]
 
-  '@rollup/rollup-linux-arm-gnueabihf@4.52.5':
-    resolution: {integrity: sha512-PsNAbcyv9CcecAUagQefwX8fQn9LQ4nZkpDboBOttmyffnInRy8R8dSg6hxxl2Re5QhHBf6FYIDhIj5v982ATQ==}
+  '@rollup/rollup-linux-arm-gnueabihf@4.59.0':
+    resolution: {integrity: sha512-t4ONHboXi/3E0rT6OZl1pKbl2Vgxf9vJfWgmUoCEVQVxhW6Cw/c8I6hbbu7DAvgp82RKiH7TpLwxnJeKv2pbsw==}
     cpu: [arm]
     os: [linux]
 
-  '@rollup/rollup-linux-arm-musleabihf@4.52.5':
-    resolution: {integrity: sha512-Fw4tysRutyQc/wwkmcyoqFtJhh0u31K+Q6jYjeicsGJJ7bbEq8LwPWV/w0cnzOqR2m694/Af6hpFayLJZkG2VQ==}
+  '@rollup/rollup-linux-arm-musleabihf@4.59.0':
+    resolution: {integrity: sha512-CikFT7aYPA2ufMD086cVORBYGHffBo4K8MQ4uPS/ZnY54GKj36i196u8U+aDVT2LX4eSMbyHtyOh7D7Zvk2VvA==}
     cpu: [arm]
     os: [linux]
 
-  '@rollup/rollup-linux-arm64-gnu@4.52.5':
-    resolution: {integrity: sha512-a+3wVnAYdQClOTlyapKmyI6BLPAFYs0JM8HRpgYZQO02rMR09ZcV9LbQB+NL6sljzG38869YqThrRnfPMCDtZg==}
+  '@rollup/rollup-linux-arm64-gnu@4.59.0':
+    resolution: {integrity: sha512-jYgUGk5aLd1nUb1CtQ8E+t5JhLc9x5WdBKew9ZgAXg7DBk0ZHErLHdXM24rfX+bKrFe+Xp5YuJo54I5HFjGDAA==}
     cpu: [arm64]
     os: [linux]
 
-  '@rollup/rollup-linux-arm64-musl@4.52.5':
-    resolution: {integrity: sha512-AvttBOMwO9Pcuuf7m9PkC1PUIKsfaAJ4AYhy944qeTJgQOqJYJ9oVl2nYgY7Rk0mkbsuOpCAYSs6wLYB2Xiw0Q==}
+  '@rollup/rollup-linux-arm64-musl@4.59.0':
+    resolution: {integrity: sha512-peZRVEdnFWZ5Bh2KeumKG9ty7aCXzzEsHShOZEFiCQlDEepP1dpUl/SrUNXNg13UmZl+gzVDPsiCwnV1uI0RUA==}
     cpu: [arm64]
     os: [linux]
 
-  '@rollup/rollup-linux-loong64-gnu@4.52.5':
-    resolution: {integrity: sha512-DkDk8pmXQV2wVrF6oq5tONK6UHLz/XcEVow4JTTerdeV1uqPeHxwcg7aFsfnSm9L+OO8WJsWotKM2JJPMWrQtA==}
+  '@rollup/rollup-linux-loong64-gnu@4.59.0':
+    resolution: {integrity: sha512-gbUSW/97f7+r4gHy3Jlup8zDG190AuodsWnNiXErp9mT90iCy9NKKU0Xwx5k8VlRAIV2uU9CsMnEFg/xXaOfXg==}
     cpu: [loong64]
     os: [linux]
 
-  '@rollup/rollup-linux-ppc64-gnu@4.52.5':
-    resolution: {integrity: sha512-W/b9ZN/U9+hPQVvlGwjzi+Wy4xdoH2I8EjaCkMvzpI7wJUs8sWJ03Rq96jRnHkSrcHTpQe8h5Tg3ZzUPGauvAw==}
+  '@rollup/rollup-linux-loong64-musl@4.59.0':
+    resolution: {integrity: sha512-yTRONe79E+o0FWFijasoTjtzG9EBedFXJMl888NBEDCDV9I2wGbFFfJQQe63OijbFCUZqxpHz1GzpbtSFikJ4Q==}
+    cpu: [loong64]
+    os: [linux]
+
+  '@rollup/rollup-linux-ppc64-gnu@4.59.0':
+    resolution: {integrity: sha512-sw1o3tfyk12k3OEpRddF68a1unZ5VCN7zoTNtSn2KndUE+ea3m3ROOKRCZxEpmT9nsGnogpFP9x6mnLTCaoLkA==}
     cpu: [ppc64]
     os: [linux]
 
-  '@rollup/rollup-linux-riscv64-gnu@4.52.5':
-    resolution: {integrity: sha512-sjQLr9BW7R/ZiXnQiWPkErNfLMkkWIoCz7YMn27HldKsADEKa5WYdobaa1hmN6slu9oWQbB6/jFpJ+P2IkVrmw==}
+  '@rollup/rollup-linux-ppc64-musl@4.59.0':
+    resolution: {integrity: sha512-+2kLtQ4xT3AiIxkzFVFXfsmlZiG5FXYW7ZyIIvGA7Bdeuh9Z0aN4hVyXS/G1E9bTP/vqszNIN/pUKCk/BTHsKA==}
+    cpu: [ppc64]
+    os: [linux]
+
+  '@rollup/rollup-linux-riscv64-gnu@4.59.0':
+    resolution: {integrity: sha512-NDYMpsXYJJaj+I7UdwIuHHNxXZ/b/N2hR15NyH3m2qAtb/hHPA4g4SuuvrdxetTdndfj9b1WOmy73kcPRoERUg==}
     cpu: [riscv64]
     os: [linux]
 
-  '@rollup/rollup-linux-riscv64-musl@4.52.5':
-    resolution: {integrity: sha512-hq3jU/kGyjXWTvAh2awn8oHroCbrPm8JqM7RUpKjalIRWWXE01CQOf/tUNWNHjmbMHg/hmNCwc/Pz3k1T/j/Lg==}
+  '@rollup/rollup-linux-riscv64-musl@4.59.0':
+    resolution: {integrity: sha512-nLckB8WOqHIf1bhymk+oHxvM9D3tyPndZH8i8+35p/1YiVoVswPid2yLzgX7ZJP0KQvnkhM4H6QZ5m0LzbyIAg==}
     cpu: [riscv64]
     os: [linux]
 
-  '@rollup/rollup-linux-s390x-gnu@4.52.5':
-    resolution: {integrity: sha512-gn8kHOrku8D4NGHMK1Y7NA7INQTRdVOntt1OCYypZPRt6skGbddska44K8iocdpxHTMMNui5oH4elPH4QOLrFQ==}
+  '@rollup/rollup-linux-s390x-gnu@4.59.0':
+    resolution: {integrity: sha512-oF87Ie3uAIvORFBpwnCvUzdeYUqi2wY6jRFWJAy1qus/udHFYIkplYRW+wo+GRUP4sKzYdmE1Y3+rY5Gc4ZO+w==}
     cpu: [s390x]
     os: [linux]
 
-  '@rollup/rollup-linux-x64-gnu@4.52.5':
-    resolution: {integrity: sha512-hXGLYpdhiNElzN770+H2nlx+jRog8TyynpTVzdlc6bndktjKWyZyiCsuDAlpd+j+W+WNqfcyAWz9HxxIGfZm1Q==}
+  '@rollup/rollup-linux-x64-gnu@4.59.0':
+    resolution: {integrity: sha512-3AHmtQq/ppNuUspKAlvA8HtLybkDflkMuLK4DPo77DfthRb71V84/c4MlWJXixZz4uruIH4uaa07IqoAkG64fg==}
     cpu: [x64]
     os: [linux]
 
-  '@rollup/rollup-linux-x64-musl@4.52.5':
-    resolution: {integrity: sha512-arCGIcuNKjBoKAXD+y7XomR9gY6Mw7HnFBv5Rw7wQRvwYLR7gBAgV7Mb2QTyjXfTveBNFAtPt46/36vV9STLNg==}
+  '@rollup/rollup-linux-x64-musl@4.59.0':
+    resolution: {integrity: sha512-2UdiwS/9cTAx7qIUZB/fWtToJwvt0Vbo0zmnYt7ED35KPg13Q0ym1g442THLC7VyI6JfYTP4PiSOWyoMdV2/xg==}
     cpu: [x64]
     os: [linux]
 
-  '@rollup/rollup-openharmony-arm64@4.52.5':
-    resolution: {integrity: sha512-QoFqB6+/9Rly/RiPjaomPLmR/13cgkIGfA40LHly9zcH1S0bN2HVFYk3a1eAyHQyjs3ZJYlXvIGtcCs5tko9Cw==}
+  '@rollup/rollup-openbsd-x64@4.59.0':
+    resolution: {integrity: sha512-M3bLRAVk6GOwFlPTIxVBSYKUaqfLrn8l0psKinkCFxl4lQvOSz8ZrKDz2gxcBwHFpci0B6rttydI4IpS4IS/jQ==}
+    cpu: [x64]
+    os: [openbsd]
+
+  '@rollup/rollup-openharmony-arm64@4.59.0':
+    resolution: {integrity: sha512-tt9KBJqaqp5i5HUZzoafHZX8b5Q2Fe7UjYERADll83O4fGqJ49O1FsL6LpdzVFQcpwvnyd0i+K/VSwu/o/nWlA==}
     cpu: [arm64]
     os: [openharmony]
 
-  '@rollup/rollup-win32-arm64-msvc@4.52.5':
-    resolution: {integrity: sha512-w0cDWVR6MlTstla1cIfOGyl8+qb93FlAVutcor14Gf5Md5ap5ySfQ7R9S/NjNaMLSFdUnKGEasmVnu3lCMqB7w==}
+  '@rollup/rollup-win32-arm64-msvc@4.59.0':
+    resolution: {integrity: sha512-V5B6mG7OrGTwnxaNUzZTDTjDS7F75PO1ae6MJYdiMu60sq0CqN5CVeVsbhPxalupvTX8gXVSU9gq+Rx1/hvu6A==}
     cpu: [arm64]
     os: [win32]
 
-  '@rollup/rollup-win32-ia32-msvc@4.52.5':
-    resolution: {integrity: sha512-Aufdpzp7DpOTULJCuvzqcItSGDH73pF3ko/f+ckJhxQyHtp67rHw3HMNxoIdDMUITJESNE6a8uh4Lo4SLouOUg==}
+  '@rollup/rollup-win32-ia32-msvc@4.59.0':
+    resolution: {integrity: sha512-UKFMHPuM9R0iBegwzKF4y0C4J9u8C6MEJgFuXTBerMk7EJ92GFVFYBfOZaSGLu6COf7FxpQNqhNS4c4icUPqxA==}
     cpu: [ia32]
     os: [win32]
 
-  '@rollup/rollup-win32-x64-gnu@4.52.5':
-    resolution: {integrity: sha512-UGBUGPFp1vkj6p8wCRraqNhqwX/4kNQPS57BCFc8wYh0g94iVIW33wJtQAx3G7vrjjNtRaxiMUylM0ktp/TRSQ==}
+  '@rollup/rollup-win32-x64-gnu@4.59.0':
+    resolution: {integrity: sha512-laBkYlSS1n2L8fSo1thDNGrCTQMmxjYY5G0WFWjFFYZkKPjsMBsgJfGf4TLxXrF6RyhI60L8TMOjBMvXiTcxeA==}
     cpu: [x64]
     os: [win32]
 
-  '@rollup/rollup-win32-x64-msvc@4.52.5':
-    resolution: {integrity: sha512-TAcgQh2sSkykPRWLrdyy2AiceMckNf5loITqXxFI5VuQjS5tSuw3WlwdN8qv8vzjLAUTvYaH/mVjSFpbkFbpTg==}
+  '@rollup/rollup-win32-x64-msvc@4.59.0':
+    resolution: {integrity: sha512-2HRCml6OztYXyJXAvdDXPKcawukWY2GpR5/nxKp4iBgiO3wcoEGkAaqctIbZcNB6KlUQBIqt8VYkNSj2397EfA==}
     cpu: [x64]
     os: [win32]
 
@@ -876,11 +891,12 @@ packages:
     peerDependencies:
       acorn: ^8.9.0
 
-  '@sveltejs/eslint-config@8.3.5':
-    resolution: {integrity: sha512-f8g5v1GNQePIJq6Rh3mf0riXx+7+IsRaTS7nn8w7r2RZFPPkuBAHGcHST9BTJOQb5UCSnPmst7BJHEDIlVtP3A==}
+  '@sveltejs/eslint-config@9.0.0':
+    resolution: {integrity: sha512-3u9VUYlU0Mc/8Bhc7eRAPgJuUBMaKHzoE8r50WrnVujoxBLW4zfPckR/BFGGNeVUh0F7QGAtxGkV/5pL6CE1Ng==}
     peerDependencies:
+      '@eslint/js': '>= 10'
       '@stylistic/eslint-plugin-js': '>= 1'
-      eslint: '>= 9'
+      eslint: '>= 10'
       eslint-config-prettier: '>= 9'
       eslint-plugin-n: '>= 17'
       eslint-plugin-svelte: '>= 3'
@@ -939,63 +955,63 @@ packages:
   '@types/trusted-types@2.0.7':
     resolution: {integrity: sha512-ScaPdn1dQczgbl0QFTeTOmVHFULt394XJgOQNoyVhZ6r2vLnMLJfBPd53SB52T/3G36VI1/g2MZaX0cwDuXsfw==}
 
-  '@typescript-eslint/eslint-plugin@8.55.0':
-    resolution: {integrity: sha512-1y/MVSz0NglV1ijHC8OT49mPJ4qhPYjiK08YUQVbIOyu+5k862LKUHFkpKHWu//zmr7hDR2rhwUm6gnCGNmGBQ==}
+  '@typescript-eslint/eslint-plugin@8.56.0':
+    resolution: {integrity: sha512-lRyPDLzNCuae71A3t9NEINBiTn7swyOhvUj3MyUOxb8x6g6vPEFoOU+ZRmGMusNC3X3YMhqMIX7i8ShqhT74Pw==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      '@typescript-eslint/parser': ^8.55.0
-      eslint: ^8.57.0 || ^9.0.0
+      '@typescript-eslint/parser': ^8.56.0
+      eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
       typescript: '>=4.8.4 <6.0.0'
 
-  '@typescript-eslint/parser@8.55.0':
-    resolution: {integrity: sha512-4z2nCSBfVIMnbuu8uinj+f0o4qOeggYJLbjpPHka3KH1om7e+H9yLKTYgksTaHcGco+NClhhY2vyO3HsMH1RGw==}
+  '@typescript-eslint/parser@8.56.0':
+    resolution: {integrity: sha512-IgSWvLobTDOjnaxAfDTIHaECbkNlAlKv2j5SjpB2v7QHKv1FIfjwMy8FsDbVfDX/KjmCmYICcw7uGaXLhtsLNg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      eslint: ^8.57.0 || ^9.0.0
+      eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
       typescript: '>=4.8.4 <6.0.0'
 
-  '@typescript-eslint/project-service@8.55.0':
-    resolution: {integrity: sha512-zRcVVPFUYWa3kNnjaZGXSu3xkKV1zXy8M4nO/pElzQhFweb7PPtluDLQtKArEOGmjXoRjnUZ29NjOiF0eCDkcQ==}
+  '@typescript-eslint/project-service@8.56.0':
+    resolution: {integrity: sha512-M3rnyL1vIQOMeWxTWIW096/TtVP+8W3p/XnaFflhmcFp+U4zlxUxWj4XwNs6HbDeTtN4yun0GNTTDBw/SvufKg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       typescript: '>=4.8.4 <6.0.0'
 
-  '@typescript-eslint/scope-manager@8.55.0':
-    resolution: {integrity: sha512-fVu5Omrd3jeqeQLiB9f1YsuK/iHFOwb04bCtY4BSCLgjNbOD33ZdV6KyEqplHr+IlpgT0QTZ/iJ+wT7hvTx49Q==}
+  '@typescript-eslint/scope-manager@8.56.0':
+    resolution: {integrity: sha512-7UiO/XwMHquH+ZzfVCfUNkIXlp/yQjjnlYUyYz7pfvlK3/EyyN6BK+emDmGNyQLBtLGaYrTAI6KOw8tFucWL2w==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
-  '@typescript-eslint/tsconfig-utils@8.55.0':
-    resolution: {integrity: sha512-1R9cXqY7RQd7WuqSN47PK9EDpgFUK3VqdmbYrvWJZYDd0cavROGn+74ktWBlmJ13NXUQKlZ/iAEQHI/V0kKe0Q==}
+  '@typescript-eslint/tsconfig-utils@8.56.0':
+    resolution: {integrity: sha512-bSJoIIt4o3lKXD3xmDh9chZcjCz5Lk8xS7Rxn+6l5/pKrDpkCwtQNQQwZ2qRPk7TkUYhrq3WPIHXOXlbXP0itg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       typescript: '>=4.8.4 <6.0.0'
 
-  '@typescript-eslint/type-utils@8.55.0':
-    resolution: {integrity: sha512-x1iH2unH4qAt6I37I2CGlsNs+B9WGxurP2uyZLRz6UJoZWDBx9cJL1xVN/FiOmHEONEg6RIufdvyT0TEYIgC5g==}
+  '@typescript-eslint/type-utils@8.56.0':
+    resolution: {integrity: sha512-qX2L3HWOU2nuDs6GzglBeuFXviDODreS58tLY/BALPC7iu3Fa+J7EOTwnX9PdNBxUI7Uh0ntP0YWGnxCkXzmfA==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      eslint: ^8.57.0 || ^9.0.0
+      eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
       typescript: '>=4.8.4 <6.0.0'
 
-  '@typescript-eslint/types@8.55.0':
-    resolution: {integrity: sha512-ujT0Je8GI5BJWi+/mMoR0wxwVEQaxM+pi30xuMiJETlX80OPovb2p9E8ss87gnSVtYXtJoU9U1Cowcr6w2FE0w==}
+  '@typescript-eslint/types@8.56.0':
+    resolution: {integrity: sha512-DBsLPs3GsWhX5HylbP9HNG15U0bnwut55Lx12bHB9MpXxQ+R5GC8MwQe+N1UFXxAeQDvEsEDY6ZYwX03K7Z6HQ==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
-  '@typescript-eslint/typescript-estree@8.55.0':
-    resolution: {integrity: sha512-EwrH67bSWdx/3aRQhCoxDaHM+CrZjotc2UCCpEDVqfCE+7OjKAGWNY2HsCSTEVvWH2clYQK8pdeLp42EVs+xQw==}
+  '@typescript-eslint/typescript-estree@8.56.0':
+    resolution: {integrity: sha512-ex1nTUMWrseMltXUHmR2GAQ4d+WjkZCT4f+4bVsps8QEdh0vlBsaCokKTPlnqBFqqGaxilDNJG7b8dolW2m43Q==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       typescript: '>=4.8.4 <6.0.0'
 
-  '@typescript-eslint/utils@8.55.0':
-    resolution: {integrity: sha512-BqZEsnPGdYpgyEIkDC1BadNY8oMwckftxBT+C8W0g1iKPdeqKZBtTfnvcq0nf60u7MkjFO8RBvpRGZBPw4L2ow==}
+  '@typescript-eslint/utils@8.56.0':
+    resolution: {integrity: sha512-RZ3Qsmi2nFGsS+n+kjLAYDPVlrzf7UhTffrDIKr+h2yzAlYP/y5ZulU0yeDEPItos2Ph46JAL5P/On3pe7kDIQ==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      eslint: ^8.57.0 || ^9.0.0
+      eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
       typescript: '>=4.8.4 <6.0.0'
 
-  '@typescript-eslint/visitor-keys@8.55.0':
-    resolution: {integrity: sha512-AxNRwEie8Nn4eFS1FzDMJWIISMGoXMb037sgCBJ3UR6o0fQTzr2tqN9WT+DkWJPhIdQCfV7T6D387566VtnCJA==}
+  '@typescript-eslint/visitor-keys@8.56.0':
+    resolution: {integrity: sha512-q+SL+b+05Ud6LbEE35qe4A99P+htKTKVbyiNEe45eCbJFyh/HVK9QXwlrbz+Q4L8SOW4roxSVwXYj4DMBT7Ieg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
   '@vitest/coverage-v8@2.1.9':
@@ -1046,6 +1062,11 @@ packages:
     engines: {node: '>=0.4.0'}
     hasBin: true
 
+  acorn@8.16.0:
+    resolution: {integrity: sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw==}
+    engines: {node: '>=0.4.0'}
+    hasBin: true
+
   agent-base@7.1.1:
     resolution: {integrity: sha512-H0TSyFNDMomMNJQBn8wFV5YC/2eJ+VXECwOadZJT554xP6cODZHPX3H9QMQECxvrgiSOP1pHjy1sMWQVYJOUOA==}
     engines: {node: '>= 14'}
@@ -1246,8 +1267,8 @@ packages:
     engines: {node: '>=0.10'}
     hasBin: true
 
-  devalue@5.6.2:
-    resolution: {integrity: sha512-nPRkjWzzDQlsejL1WVifk5rvcFi/y1onBRxjaFMjZeR9mFpqu2gmAZ9xUB9/IEanEP/vBtGeGganC/GO1fmufg==}
+  devalue@5.6.3:
+    resolution: {integrity: sha512-nc7XjUU/2Lb+SvEFVGcWLiKkzfw8+qHI7zn8WYXKkLMgfGSHbgCEaR6bJpev8Cm6Rmrb19Gfd/tZvGqx9is3wg==}
 
   dir-glob@3.0.1:
     resolution: {integrity: sha512-WkrWp9GR4KXfKGYzOLmTuGVi1UWFfws377n9cc55/tb6DuqyF6pcQ5AbiHEshaDpY9v6oaSr2XCDidGmMwdzIA==}
@@ -1272,8 +1293,8 @@ packages:
   emoji-regex@9.2.2:
     resolution: {integrity: sha512-L18DaJsXSUk2+42pv8mLs5jJT2hqFkFE4j21wOmgbUqsZ2hL72NsUU785g9RXgo3s0ZNgVl42TiHp3ZtOv/Vyg==}
 
-  enhanced-resolve@5.18.3:
-    resolution: {integrity: sha512-d4lC8xfavMeBjzGr2vECC3fsGXziXZQyJxD868h2M/mBI3PwAuODxAkLkq5HYuvrPYcUtiLzsTo8U3PgX3Ocww==}
+  enhanced-resolve@5.19.0:
+    resolution: {integrity: sha512-phv3E1Xl4tQOShqSte26C7Fl84EwUdZsyOuSSk9qtAGyyQs2s3jJzComh+Abf4g187lUUAvH+H26omrqia2aGg==}
     engines: {node: '>=10.13.0'}
 
   enquirer@2.4.1:
@@ -1327,8 +1348,8 @@ packages:
     peerDependencies:
       eslint: '>=9.0.0'
 
-  eslint-plugin-n@17.16.1:
-    resolution: {integrity: sha512-/7FVAwjUrix9P5lycnsYRIQRwFo/DZROD+ZXWLpE+/EZWLyuLvyFaRdAPYJSz+nlAdZIZp+LAzlBerQSVYUNFg==}
+  eslint-plugin-n@17.24.0:
+    resolution: {integrity: sha512-/gC7/KAYmfNnPNOb3eu8vw+TdVnV0zhdQwexsw6FLXbhzroVj20vRn2qL8lDWDGnAQ2J8DhdfvXxX9EoxvERvw==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
       eslint: '>=8.23.0'
@@ -1502,8 +1523,8 @@ packages:
   function-bind@1.1.2:
     resolution: {integrity: sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==}
 
-  get-tsconfig@4.13.0:
-    resolution: {integrity: sha512-1VKTZJCwBrvbd+Wn3AOgQP/2Av+TfTCOlE4AcRJE72W1ksZXbAx8PPBR9RzgTeSPzlPMHrbANMH3LbltH73wxQ==}
+  get-tsconfig@4.13.6:
+    resolution: {integrity: sha512-shZT/QMiSHc/YBLxxOkMtgSid5HFoauqCE3/exfsEcwg1WkeqjG+V40yBbBrsD+jW2HDXcs28xOfcbm2jI8Ddw==}
 
   glob-parent@5.1.2:
     resolution: {integrity: sha512-AOIgSQCepiJYwP3ARnGx+5VnTu2HBYdzbGP45eLw1vr3zB3vZLeyed1sC9hnbcOc9/SrMyM5RPQrkGz4aS9Zow==}
@@ -1534,6 +1555,9 @@ packages:
     resolution: {integrity: sha512-jhIXaOzy1sb8IyocaruWSn1TjmnBVs8Ayhcy83rmxNJ8q2uWKCAj3CnJY+KpGSXCueAPc0i05kVvVKtP1t9S3g==}
     engines: {node: '>=10'}
 
+  globrex@0.1.2:
+    resolution: {integrity: sha512-uHJgbwAMwNFf5mLst7IWLNg14x1CkeqglJb/K3doi4dw6q2IvAAmM/Y81kevy83wP+Sst+nutFTYOGg3d1lsxg==}
+
   graceful-fs@4.2.11:
     resolution: {integrity: sha512-RbJ5/jmFcNNCcDV5o9eTnBLJ/HszWV0P73bc+Ff4nS/rJj+YaS6IGyiOL0VoBYX+l1Wrl3k63h/KrH+nhJ0XvQ==}
 
@@ -2068,8 +2092,8 @@ packages:
     resolution: {integrity: sha512-U9nH88a3fc/ekCF1l0/UP1IosiuIjyTh7hBvXVMHYgVcfGvt897Xguj2UOLDeI5BG2m7/uwyaLVT6fbtCwTyzw==}
     engines: {iojs: '>=1.0.0', node: '>=0.10.0'}
 
-  rollup@4.52.5:
-    resolution: {integrity: sha512-3GuObel8h7Kqdjt0gxkEzaifHTqLVW56Y/bjN7PSQtkKr0w3V/QYSdt6QWYtd7A1xUtYQigtdUfgj1RvWVtorw==}
+  rollup@4.59.0:
+    resolution: {integrity: sha512-2oMpl67a3zCH9H79LeMcbDhXW/UmWG/y2zuqnF2jQq5uq9TbM9TVyXvA4+t+ne2IIkBdrLpAaRQAvo7YI/Yyeg==}
     engines: {node: '>=18.0.0', npm: '>=8.0.0'}
     hasBin: true
 
@@ -2107,6 +2131,11 @@ packages:
     engines: {node: '>=10'}
     hasBin: true
 
+  semver@7.7.4:
+    resolution: {integrity: sha512-vFKC2IEtQnVhpT78h1Yp8wzwrf8CM+MzKMHGJZfBtzhZNycRFnXsHk6E5TxIkkMsgNS7mdX3AGB7x2QM2di4lA==}
+    engines: {node: '>=10'}
+    hasBin: true
+
   serialize-javascript@6.0.2:
     resolution: {integrity: sha512-Saa1xPByTTq2gdeFZYLLo+RFE35NHZkAbqZeWNd3BpzppeVisAqpDjcp8dyf6uIvEqJRd46jemmyA4iFIeVk8g==}
 
@@ -2297,11 +2326,11 @@ packages:
     resolution: {integrity: sha512-XleUoc9uwGXqjWwXaUTZAmzMcFZ5858QA2vvx1Ur5xIcixXIP+8LnFDgRplU30us6teqdlskFfu+ae4K79Ooew==}
     engines: {node: '>= 0.8.0'}
 
-  typescript-eslint@8.55.0:
-    resolution: {integrity: sha512-HE4wj+r5lmDVS9gdaN0/+iqNvPZwGfnJ5lZuz7s5vLlg9ODw0bIiiETaios9LvFI1U94/VBXGm3CB2Y5cNFMpw==}
+  typescript-eslint@8.56.0:
+    resolution: {integrity: sha512-c7toRLrotJ9oixgdW7liukZpsnq5CZ7PuKztubGYlNppuTqhIoWfhgHo/7EU0v06gS2l/x0i2NEFK1qMIf0rIg==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
     peerDependencies:
-      eslint: ^8.57.0 || ^9.0.0
+      eslint: ^8.57.0 || ^9.0.0 || ^10.0.0
       typescript: '>=4.8.4 <6.0.0'
 
   typescript@5.5.4:
@@ -3008,9 +3037,9 @@ snapshots:
 
   '@polka/url@1.0.0-next.25': {}
 
-  '@rollup/plugin-commonjs@28.0.1(rollup@4.52.5)':
+  '@rollup/plugin-commonjs@28.0.1(rollup@4.59.0)':
     dependencies:
-      '@rollup/pluginutils': 5.1.0(rollup@4.52.5)
+      '@rollup/pluginutils': 5.1.0(rollup@4.59.0)
       commondir: 1.0.1
       estree-walker: 2.0.2
       fdir: 6.5.0(picomatch@4.0.3)
@@ -3018,108 +3047,117 @@ snapshots:
       magic-string: 0.30.17
       picomatch: 4.0.3
     optionalDependencies:
-      rollup: 4.52.5
+      rollup: 4.59.0
 
-  '@rollup/plugin-node-resolve@15.3.0(rollup@4.52.5)':
+  '@rollup/plugin-node-resolve@15.3.0(rollup@4.59.0)':
     dependencies:
-      '@rollup/pluginutils': 5.1.0(rollup@4.52.5)
+      '@rollup/pluginutils': 5.1.0(rollup@4.59.0)
       '@types/resolve': 1.20.2
       deepmerge: 4.3.1
       is-module: 1.0.0
       resolve: 1.22.8
     optionalDependencies:
-      rollup: 4.52.5
+      rollup: 4.59.0
 
-  '@rollup/plugin-terser@0.4.4(rollup@4.52.5)':
+  '@rollup/plugin-terser@0.4.4(rollup@4.59.0)':
     dependencies:
       serialize-javascript: 6.0.2
       smob: 1.4.1
       terser: 5.27.0
     optionalDependencies:
-      rollup: 4.52.5
+      rollup: 4.59.0
 
-  '@rollup/plugin-virtual@3.0.2(rollup@4.52.5)':
+  '@rollup/plugin-virtual@3.0.2(rollup@4.59.0)':
     optionalDependencies:
-      rollup: 4.52.5
+      rollup: 4.59.0
 
-  '@rollup/pluginutils@5.1.0(rollup@4.52.5)':
+  '@rollup/pluginutils@5.1.0(rollup@4.59.0)':
     dependencies:
       '@types/estree': 1.0.8
       estree-walker: 2.0.2
       picomatch: 2.3.1
     optionalDependencies:
-      rollup: 4.52.5
+      rollup: 4.59.0
+
+  '@rollup/rollup-android-arm-eabi@4.59.0':
+    optional: true
 
-  '@rollup/rollup-android-arm-eabi@4.52.5':
+  '@rollup/rollup-android-arm64@4.59.0':
     optional: true
 
-  '@rollup/rollup-android-arm64@4.52.5':
+  '@rollup/rollup-darwin-arm64@4.59.0':
     optional: true
 
-  '@rollup/rollup-darwin-arm64@4.52.5':
+  '@rollup/rollup-darwin-x64@4.59.0':
     optional: true
 
-  '@rollup/rollup-darwin-x64@4.52.5':
+  '@rollup/rollup-freebsd-arm64@4.59.0':
     optional: true
 
-  '@rollup/rollup-freebsd-arm64@4.52.5':
+  '@rollup/rollup-freebsd-x64@4.59.0':
     optional: true
 
-  '@rollup/rollup-freebsd-x64@4.52.5':
+  '@rollup/rollup-linux-arm-gnueabihf@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-arm-gnueabihf@4.52.5':
+  '@rollup/rollup-linux-arm-musleabihf@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-arm-musleabihf@4.52.5':
+  '@rollup/rollup-linux-arm64-gnu@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-arm64-gnu@4.52.5':
+  '@rollup/rollup-linux-arm64-musl@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-arm64-musl@4.52.5':
+  '@rollup/rollup-linux-loong64-gnu@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-loong64-gnu@4.52.5':
+  '@rollup/rollup-linux-loong64-musl@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-ppc64-gnu@4.52.5':
+  '@rollup/rollup-linux-ppc64-gnu@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-riscv64-gnu@4.52.5':
+  '@rollup/rollup-linux-ppc64-musl@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-riscv64-musl@4.52.5':
+  '@rollup/rollup-linux-riscv64-gnu@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-s390x-gnu@4.52.5':
+  '@rollup/rollup-linux-riscv64-musl@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-x64-gnu@4.52.5':
+  '@rollup/rollup-linux-s390x-gnu@4.59.0':
     optional: true
 
-  '@rollup/rollup-linux-x64-musl@4.52.5':
+  '@rollup/rollup-linux-x64-gnu@4.59.0':
     optional: true
 
-  '@rollup/rollup-openharmony-arm64@4.52.5':
+  '@rollup/rollup-linux-x64-musl@4.59.0':
     optional: true
 
-  '@rollup/rollup-win32-arm64-msvc@4.52.5':
+  '@rollup/rollup-openbsd-x64@4.59.0':
     optional: true
 
-  '@rollup/rollup-win32-ia32-msvc@4.52.5':
+  '@rollup/rollup-openharmony-arm64@4.59.0':
     optional: true
 
-  '@rollup/rollup-win32-x64-gnu@4.52.5':
+  '@rollup/rollup-win32-arm64-msvc@4.59.0':
     optional: true
 
-  '@rollup/rollup-win32-x64-msvc@4.52.5':
+  '@rollup/rollup-win32-ia32-msvc@4.59.0':
+    optional: true
+
+  '@rollup/rollup-win32-x64-gnu@4.59.0':
+    optional: true
+
+  '@rollup/rollup-win32-x64-msvc@4.59.0':
     optional: true
 
   '@stylistic/eslint-plugin-js@1.8.0(eslint@10.0.0)':
     dependencies:
       '@types/eslint': 8.56.12
-      acorn: 8.15.0
+      acorn: 8.16.0
       escape-string-regexp: 4.0.0
       eslint: 10.0.0
       eslint-visitor-keys: 3.4.3
@@ -3129,16 +3167,17 @@ snapshots:
     dependencies:
       acorn: 8.15.0
 
-  '@sveltejs/eslint-config@8.3.5(@stylistic/eslint-plugin-js@1.8.0(eslint@10.0.0))(eslint-config-prettier@9.1.0(eslint@10.0.0))(eslint-plugin-n@17.16.1(eslint@10.0.0)(typescript@5.5.4))(eslint-plugin-svelte@3.15.0(eslint@10.0.0)(svelte@packages+svelte))(eslint@10.0.0)(typescript-eslint@8.55.0(eslint@10.0.0)(typescript@5.5.4))(typescript@5.5.4)':
+  '@sveltejs/eslint-config@9.0.0(@eslint/js@10.0.1(eslint@10.0.0))(@stylistic/eslint-plugin-js@1.8.0(eslint@10.0.0))(eslint-config-prettier@9.1.0(eslint@10.0.0))(eslint-plugin-n@17.24.0(eslint@10.0.0)(typescript@5.5.4))(eslint-plugin-svelte@3.15.0(eslint@10.0.0)(svelte@packages+svelte))(eslint@10.0.0)(typescript-eslint@8.56.0(eslint@10.0.0)(typescript@5.5.4))(typescript@5.5.4)':
     dependencies:
+      '@eslint/js': 10.0.1(eslint@10.0.0)
       '@stylistic/eslint-plugin-js': 1.8.0(eslint@10.0.0)
       eslint: 10.0.0
       eslint-config-prettier: 9.1.0(eslint@10.0.0)
-      eslint-plugin-n: 17.16.1(eslint@10.0.0)(typescript@5.5.4)
+      eslint-plugin-n: 17.24.0(eslint@10.0.0)(typescript@5.5.4)
       eslint-plugin-svelte: 3.15.0(eslint@10.0.0)(svelte@packages+svelte)
       globals: 17.3.0
       typescript: 5.5.4
-      typescript-eslint: 8.55.0(eslint@10.0.0)(typescript@5.5.4)
+      typescript-eslint: 8.56.0(eslint@10.0.0)(typescript@5.5.4)
 
   '@sveltejs/vite-plugin-svelte-inspector@5.0.1(@sveltejs/vite-plugin-svelte@6.2.0(svelte@packages+svelte)(vite@7.1.11(@types/node@24.5.2)(lightningcss@1.23.0)(sass@1.70.0)(terser@5.27.0)))(svelte@packages+svelte)(vite@7.1.11(@types/node@24.5.2)(lightningcss@1.23.0)(sass@1.70.0)(terser@5.27.0))':
     dependencies:
@@ -3197,14 +3236,14 @@ snapshots:
 
   '@types/trusted-types@2.0.7': {}
 
-  '@typescript-eslint/eslint-plugin@8.55.0(@typescript-eslint/parser@8.55.0(eslint@10.0.0)(typescript@5.5.4))(eslint@10.0.0)(typescript@5.5.4)':
+  '@typescript-eslint/eslint-plugin@8.56.0(@typescript-eslint/parser@8.56.0(eslint@10.0.0)(typescript@5.5.4))(eslint@10.0.0)(typescript@5.5.4)':
     dependencies:
       '@eslint-community/regexpp': 4.12.2
-      '@typescript-eslint/parser': 8.55.0(eslint@10.0.0)(typescript@5.5.4)
-      '@typescript-eslint/scope-manager': 8.55.0
-      '@typescript-eslint/type-utils': 8.55.0(eslint@10.0.0)(typescript@5.5.4)
-      '@typescript-eslint/utils': 8.55.0(eslint@10.0.0)(typescript@5.5.4)
-      '@typescript-eslint/visitor-keys': 8.55.0
+      '@typescript-eslint/parser': 8.56.0(eslint@10.0.0)(typescript@5.5.4)
+      '@typescript-eslint/scope-manager': 8.56.0
+      '@typescript-eslint/type-utils': 8.56.0(eslint@10.0.0)(typescript@5.5.4)
+      '@typescript-eslint/utils': 8.56.0(eslint@10.0.0)(typescript@5.5.4)
+      '@typescript-eslint/visitor-keys': 8.56.0
       eslint: 10.0.0
       ignore: 7.0.5
       natural-compare: 1.4.0
@@ -3213,41 +3252,41 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  '@typescript-eslint/parser@8.55.0(eslint@10.0.0)(typescript@5.5.4)':
+  '@typescript-eslint/parser@8.56.0(eslint@10.0.0)(typescript@5.5.4)':
     dependencies:
-      '@typescript-eslint/scope-manager': 8.55.0
-      '@typescript-eslint/types': 8.55.0
-      '@typescript-eslint/typescript-estree': 8.55.0(typescript@5.5.4)
-      '@typescript-eslint/visitor-keys': 8.55.0
+      '@typescript-eslint/scope-manager': 8.56.0
+      '@typescript-eslint/types': 8.56.0
+      '@typescript-eslint/typescript-estree': 8.56.0(typescript@5.5.4)
+      '@typescript-eslint/visitor-keys': 8.56.0
       debug: 4.4.3
       eslint: 10.0.0
       typescript: 5.5.4
     transitivePeerDependencies:
       - supports-color
 
-  '@typescript-eslint/project-service@8.55.0(typescript@5.5.4)':
+  '@typescript-eslint/project-service@8.56.0(typescript@5.5.4)':
     dependencies:
-      '@typescript-eslint/tsconfig-utils': 8.55.0(typescript@5.5.4)
-      '@typescript-eslint/types': 8.55.0
+      '@typescript-eslint/tsconfig-utils': 8.56.0(typescript@5.5.4)
+      '@typescript-eslint/types': 8.56.0
       debug: 4.4.3
       typescript: 5.5.4
     transitivePeerDependencies:
       - supports-color
 
-  '@typescript-eslint/scope-manager@8.55.0':
+  '@typescript-eslint/scope-manager@8.56.0':
     dependencies:
-      '@typescript-eslint/types': 8.55.0
-      '@typescript-eslint/visitor-keys': 8.55.0
+      '@typescript-eslint/types': 8.56.0
+      '@typescript-eslint/visitor-keys': 8.56.0
 
-  '@typescript-eslint/tsconfig-utils@8.55.0(typescript@5.5.4)':
+  '@typescript-eslint/tsconfig-utils@8.56.0(typescript@5.5.4)':
     dependencies:
       typescript: 5.5.4
 
-  '@typescript-eslint/type-utils@8.55.0(eslint@10.0.0)(typescript@5.5.4)':
+  '@typescript-eslint/type-utils@8.56.0(eslint@10.0.0)(typescript@5.5.4)':
     dependencies:
-      '@typescript-eslint/types': 8.55.0
-      '@typescript-eslint/typescript-estree': 8.55.0(typescript@5.5.4)
-      '@typescript-eslint/utils': 8.55.0(eslint@10.0.0)(typescript@5.5.4)
+      '@typescript-eslint/types': 8.56.0
+      '@typescript-eslint/typescript-estree': 8.56.0(typescript@5.5.4)
+      '@typescript-eslint/utils': 8.56.0(eslint@10.0.0)(typescript@5.5.4)
       debug: 4.4.3
       eslint: 10.0.0
       ts-api-utils: 2.4.0(typescript@5.5.4)
@@ -3255,14 +3294,14 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  '@typescript-eslint/types@8.55.0': {}
+  '@typescript-eslint/types@8.56.0': {}
 
-  '@typescript-eslint/typescript-estree@8.55.0(typescript@5.5.4)':
+  '@typescript-eslint/typescript-estree@8.56.0(typescript@5.5.4)':
     dependencies:
-      '@typescript-eslint/project-service': 8.55.0(typescript@5.5.4)
-      '@typescript-eslint/tsconfig-utils': 8.55.0(typescript@5.5.4)
-      '@typescript-eslint/types': 8.55.0
-      '@typescript-eslint/visitor-keys': 8.55.0
+      '@typescript-eslint/project-service': 8.56.0(typescript@5.5.4)
+      '@typescript-eslint/tsconfig-utils': 8.56.0(typescript@5.5.4)
+      '@typescript-eslint/types': 8.56.0
+      '@typescript-eslint/visitor-keys': 8.56.0
       debug: 4.4.3
       minimatch: 9.0.5
       semver: 7.7.3
@@ -3272,21 +3311,21 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  '@typescript-eslint/utils@8.55.0(eslint@10.0.0)(typescript@5.5.4)':
+  '@typescript-eslint/utils@8.56.0(eslint@10.0.0)(typescript@5.5.4)':
     dependencies:
       '@eslint-community/eslint-utils': 4.9.1(eslint@10.0.0)
-      '@typescript-eslint/scope-manager': 8.55.0
-      '@typescript-eslint/types': 8.55.0
-      '@typescript-eslint/typescript-estree': 8.55.0(typescript@5.5.4)
+      '@typescript-eslint/scope-manager': 8.56.0
+      '@typescript-eslint/types': 8.56.0
+      '@typescript-eslint/typescript-estree': 8.56.0(typescript@5.5.4)
       eslint: 10.0.0
       typescript: 5.5.4
     transitivePeerDependencies:
       - supports-color
 
-  '@typescript-eslint/visitor-keys@8.55.0':
+  '@typescript-eslint/visitor-keys@8.56.0':
     dependencies:
-      '@typescript-eslint/types': 8.55.0
-      eslint-visitor-keys: 4.2.1
+      '@typescript-eslint/types': 8.56.0
+      eslint-visitor-keys: 5.0.0
 
   '@vitest/coverage-v8@2.1.9(vitest@2.1.9(@types/node@20.19.17)(jsdom@25.0.1)(lightningcss@1.23.0)(sass@1.70.0)(terser@5.27.0))':
     dependencies:
@@ -3350,8 +3389,14 @@ snapshots:
     dependencies:
       acorn: 8.15.0
 
+  acorn-jsx@5.3.2(acorn@8.16.0):
+    dependencies:
+      acorn: 8.16.0
+
   acorn@8.15.0: {}
 
+  acorn@8.16.0: {}
+
   agent-base@7.1.1:
     dependencies:
       debug: 4.4.3
@@ -3518,7 +3563,7 @@ snapshots:
   detect-libc@1.0.3:
     optional: true
 
-  devalue@5.6.2: {}
+  devalue@5.6.3: {}
 
   dir-glob@3.0.1:
     dependencies:
@@ -3544,7 +3589,7 @@ snapshots:
 
   emoji-regex@9.2.2: {}
 
-  enhanced-resolve@5.18.3:
+  enhanced-resolve@5.19.0:
     dependencies:
       graceful-fs: 4.2.11
       tapable: 2.3.0
@@ -3620,7 +3665,7 @@ snapshots:
   eslint-compat-utils@0.5.1(eslint@10.0.0):
     dependencies:
       eslint: 10.0.0
-      semver: 7.7.3
+      semver: 7.7.4
 
   eslint-config-prettier@9.1.0(eslint@10.0.0):
     dependencies:
@@ -3637,21 +3682,19 @@ snapshots:
     dependencies:
       eslint: 10.0.0
 
-  eslint-plugin-n@17.16.1(eslint@10.0.0)(typescript@5.5.4):
+  eslint-plugin-n@17.24.0(eslint@10.0.0)(typescript@5.5.4):
     dependencies:
       '@eslint-community/eslint-utils': 4.9.1(eslint@10.0.0)
-      '@typescript-eslint/utils': 8.55.0(eslint@10.0.0)(typescript@5.5.4)
-      enhanced-resolve: 5.18.3
+      enhanced-resolve: 5.19.0
       eslint: 10.0.0
       eslint-plugin-es-x: 7.8.0(eslint@10.0.0)
-      get-tsconfig: 4.13.0
+      get-tsconfig: 4.13.6
       globals: 15.15.0
+      globrex: 0.1.2
       ignore: 5.3.2
-      minimatch: 9.0.5
-      semver: 7.7.3
+      semver: 7.7.4
       ts-declaration-location: 1.0.7(typescript@5.5.4)
     transitivePeerDependencies:
-      - supports-color
       - typescript
 
   eslint-plugin-svelte@3.15.0(eslint@10.0.0)(svelte@packages+svelte):
@@ -3741,8 +3784,8 @@ snapshots:
 
   espree@9.6.1:
     dependencies:
-      acorn: 8.15.0
-      acorn-jsx: 5.3.2(acorn@8.15.0)
+      acorn: 8.16.0
+      acorn-jsx: 5.3.2(acorn@8.16.0)
       eslint-visitor-keys: 3.4.3
 
   esprima@4.0.1: {}
@@ -3851,7 +3894,7 @@ snapshots:
 
   function-bind@1.1.2: {}
 
-  get-tsconfig@4.13.0:
+  get-tsconfig@4.13.6:
     dependencies:
       resolve-pkg-maps: 1.0.0
 
@@ -3887,6 +3930,8 @@ snapshots:
       merge2: 1.4.1
       slash: 3.0.0
 
+  globrex@0.1.2: {}
+
   graceful-fs@4.2.11: {}
 
   has-flag@4.0.0: {}
@@ -4355,32 +4400,35 @@ snapshots:
 
   reusify@1.0.4: {}
 
-  rollup@4.52.5:
+  rollup@4.59.0:
     dependencies:
       '@types/estree': 1.0.8
     optionalDependencies:
-      '@rollup/rollup-android-arm-eabi': 4.52.5
-      '@rollup/rollup-android-arm64': 4.52.5
-      '@rollup/rollup-darwin-arm64': 4.52.5
-      '@rollup/rollup-darwin-x64': 4.52.5
-      '@rollup/rollup-freebsd-arm64': 4.52.5
-      '@rollup/rollup-freebsd-x64': 4.52.5
-      '@rollup/rollup-linux-arm-gnueabihf': 4.52.5
-      '@rollup/rollup-linux-arm-musleabihf': 4.52.5
-      '@rollup/rollup-linux-arm64-gnu': 4.52.5
-      '@rollup/rollup-linux-arm64-musl': 4.52.5
-      '@rollup/rollup-linux-loong64-gnu': 4.52.5
-      '@rollup/rollup-linux-ppc64-gnu': 4.52.5
-      '@rollup/rollup-linux-riscv64-gnu': 4.52.5
-      '@rollup/rollup-linux-riscv64-musl': 4.52.5
-      '@rollup/rollup-linux-s390x-gnu': 4.52.5
-      '@rollup/rollup-linux-x64-gnu': 4.52.5
-      '@rollup/rollup-linux-x64-musl': 4.52.5
-      '@rollup/rollup-openharmony-arm64': 4.52.5
-      '@rollup/rollup-win32-arm64-msvc': 4.52.5
-      '@rollup/rollup-win32-ia32-msvc': 4.52.5
-      '@rollup/rollup-win32-x64-gnu': 4.52.5
-      '@rollup/rollup-win32-x64-msvc': 4.52.5
+      '@rollup/rollup-android-arm-eabi': 4.59.0
+      '@rollup/rollup-android-arm64': 4.59.0
+      '@rollup/rollup-darwin-arm64': 4.59.0
+      '@rollup/rollup-darwin-x64': 4.59.0
+      '@rollup/rollup-freebsd-arm64': 4.59.0
+      '@rollup/rollup-freebsd-x64': 4.59.0
+      '@rollup/rollup-linux-arm-gnueabihf': 4.59.0
+      '@rollup/rollup-linux-arm-musleabihf': 4.59.0
+      '@rollup/rollup-linux-arm64-gnu': 4.59.0
+      '@rollup/rollup-linux-arm64-musl': 4.59.0
+      '@rollup/rollup-linux-loong64-gnu': 4.59.0
+      '@rollup/rollup-linux-loong64-musl': 4.59.0
+      '@rollup/rollup-linux-ppc64-gnu': 4.59.0
+      '@rollup/rollup-linux-ppc64-musl': 4.59.0
+      '@rollup/rollup-linux-riscv64-gnu': 4.59.0
+      '@rollup/rollup-linux-riscv64-musl': 4.59.0
+      '@rollup/rollup-linux-s390x-gnu': 4.59.0
+      '@rollup/rollup-linux-x64-gnu': 4.59.0
+      '@rollup/rollup-linux-x64-musl': 4.59.0
+      '@rollup/rollup-openbsd-x64': 4.59.0
+      '@rollup/rollup-openharmony-arm64': 4.59.0
+      '@rollup/rollup-win32-arm64-msvc': 4.59.0
+      '@rollup/rollup-win32-ia32-msvc': 4.59.0
+      '@rollup/rollup-win32-x64-gnu': 4.59.0
+      '@rollup/rollup-win32-x64-msvc': 4.59.0
       fsevents: 2.3.3
 
   rrweb-cssom@0.7.1: {}
@@ -4412,6 +4460,8 @@ snapshots:
 
   semver@7.7.3: {}
 
+  semver@7.7.4: {}
+
   serialize-javascript@6.0.2:
     dependencies:
       randombytes: 2.1.0
@@ -4576,12 +4626,12 @@ snapshots:
     dependencies:
       prelude-ls: 1.2.1
 
-  typescript-eslint@8.55.0(eslint@10.0.0)(typescript@5.5.4):
+  typescript-eslint@8.56.0(eslint@10.0.0)(typescript@5.5.4):
     dependencies:
-      '@typescript-eslint/eslint-plugin': 8.55.0(@typescript-eslint/parser@8.55.0(eslint@10.0.0)(typescript@5.5.4))(eslint@10.0.0)(typescript@5.5.4)
-      '@typescript-eslint/parser': 8.55.0(eslint@10.0.0)(typescript@5.5.4)
-      '@typescript-eslint/typescript-estree': 8.55.0(typescript@5.5.4)
-      '@typescript-eslint/utils': 8.55.0(eslint@10.0.0)(typescript@5.5.4)
+      '@typescript-eslint/eslint-plugin': 8.56.0(@typescript-eslint/parser@8.56.0(eslint@10.0.0)(typescript@5.5.4))(eslint@10.0.0)(typescript@5.5.4)
+      '@typescript-eslint/parser': 8.56.0(eslint@10.0.0)(typescript@5.5.4)
+      '@typescript-eslint/typescript-estree': 8.56.0(typescript@5.5.4)
+      '@typescript-eslint/utils': 8.56.0(eslint@10.0.0)(typescript@5.5.4)
       eslint: 10.0.0
       typescript: 5.5.4
     transitivePeerDependencies:
@@ -4662,7 +4712,7 @@ snapshots:
     dependencies:
       esbuild: 0.21.5
       postcss: 8.5.6
-      rollup: 4.52.5
+      rollup: 4.59.0
     optionalDependencies:
       '@types/node': 20.19.17
       fsevents: 2.3.3
@@ -4676,7 +4726,7 @@ snapshots:
       fdir: 6.5.0(picomatch@4.0.3)
       picomatch: 4.0.3
       postcss: 8.5.6
-      rollup: 4.52.5
+      rollup: 4.59.0
       tinyglobby: 0.2.15
     optionalDependencies:
       '@types/node': 24.5.2