fix(desktop): tolerate missing `obfuscated` in thumb response (#167)

The CE server's /file/thumb payload carries only `url`/`expires`, but the
cloudreve-api model required `obfuscated`, so every thumbnail request
failed deserialization and Explorer got E_FAIL for online-only
placeholders. Hydrated files were unaffected — Windows thumbs them
locally without the handler.

`obfuscated` is now #[serde(default)]: missing → false → the
time-flow decode path only runs when a server actually emits the flag.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

ROADMAP.md

@@ -231,6 +231,7 @@ Goal: Windows + macOS + Linux from the `desktop/` tree in this repo.
 - Status: (1) notifications already per-OS (`win32_notif` / `notify_rust` / `mac_notification_sys`) — no abstraction needed; (2) hydration abstracted via `drive/placeholder` cfg swap — `cfapi` on Windows, `placeholder_non_windows` full-sync adapter elsewhere (FUSE / File Provider still open); (3) CI matrix builds + tests all 3 OSes; (4) packaging: `desktop-release.yml` on `desktop-v*` tags ships .msi/.exe (Windows), .dmg (macOS), .deb/.AppImage (Linux) — MSIX deferred (needs store signing).
 - Verified on Linux: `cargo test --workspace` green (49 tests), `cargo tauri build` produces working .deb + .AppImage.
 - Feature fallback on Linux/macOS until providers land: full sync without placeholders (download-on-access still works via sync engine).
+- [x] #167 (upstream desktop#49) — online-only thumbnails missing in Explorer: root cause was a client/server contract mismatch — the CE `/file/thumb` response carries only `url`/`expires` while the `cloudreve-api` model required `obfuscated`, failing deserialization on every thumbnail request (`E_FAIL` to Explorer; hydrated files were unaffected since Windows thumbs them locally). `obfuscated` is now `#[serde(default)]`; the decode path still runs when a server emits the flag
 
 ## 7. Phase E — Android app (native, no iOS)
 

desktop/crates/cloudreve-api/src/models/explorer.rs

@@ -254,6 +254,7 @@ pub struct FileThumbResponse {
     pub url: String,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub expires: Option<String>,
+    #[serde(default)]
     pub obfuscated: bool,
 }
 
@@ -575,3 +576,32 @@ pub enum FileEvent {
     /// Batch of file events with data
     Event(Vec<FileEventData>),
 }
+
+#[cfg(test)]
+mod tests {
+    use super::FileThumbResponse;
+
+    #[test]
+    fn thumb_response_without_obfuscated_field_deserializes() {
+        // The CE server's /file/thumb response carries only `url`/`expires`;
+        // a missing `obfuscated` flag must not fail deserialization — otherwise
+        // every thumbnail request errors out and Explorer shows no thumbnails
+        // for online-only placeholders.
+        let res: FileThumbResponse =
+            serde_json::from_str(r#"{"url":"https://example.com/t.jpg","expires":null}"#)
+                .expect("response without `obfuscated` must deserialize");
+        assert!(!res.obfuscated);
+        assert_eq!(res.url, "https://example.com/t.jpg");
+        assert!(res.expires.is_none());
+    }
+
+    #[test]
+    fn thumb_response_with_obfuscated_field_deserializes() {
+        let res: FileThumbResponse = serde_json::from_str(
+            r#"{"url":"abc","expires":"2026-01-01T00:00:00Z","obfuscated":true}"#,
+        )
+        .expect("response with `obfuscated` must deserialize");
+        assert!(res.obfuscated);
+        assert_eq!(res.expires.as_deref(), Some("2026-01-01T00:00:00Z"));
+    }
+}