fix: ensure inspect fires on prop changes (#10468)

* fix: ensure inspect fires on prop changes

* fix: ensure inspect fires on prop changes

* fix: ensure inspect fires on prop changes

.changeset/spicy-jeans-deliver.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: ensure inspect fires on prop changes

packages/svelte/src/internal/client/runtime.js

@@ -1646,7 +1646,8 @@ export function prop(props, key, flags, initial) {
 		var current = get(current_value);
 
 		// legacy nonsense — need to ensure the source is invalidated when necessary
-		if (is_signals_recorded) {
+		// also needed for when handling inspect logic so we can inspect the correct source signal
+		if (is_signals_recorded || (DEV && inspect_fn)) {
 			// set this so that we don't reset to the parent value if `d`
 			// is invalidated because of `invalidate_inner_signals` (rather
 			// than because the parent or child value changed)