feat: massive chat reliability + UX pass (web/desktop/mobile/vscode) (#593)

## Added Features
- Add VS Code save-as-image flow for assistant messages via webview bridge + native save dialog.
- Add hourly desktop update checks after startup.
- Add new tool output display mode: `Changes` (auto-expand edit/write/patch only; keep activity expanded; mode guidance text).
- Add GitHub PR attachment flow in chat input with PR picker + attached PR chip/details.
- Add mobile overlay presentation for GitHub Issue and PR pickers (shared with desktop picker content).

## Fixes
- Save-gate project icon updates until explicit Save; allow icon removal with same save-gated behavior.
- Restore clickable chat action buttons in sticky header mode (desktop + Firefox hit-target issue).
- Clamp sticky user messages to bounded chat height and allow internal scrolling.
- Prevent drawer context crash during iPad/tablet orientation switching.
- Improve text-selection action menu placement on narrow screens.
- Move assistant message time into clock tooltip; keep duration display clean.
- Hide `Link GitHub Issue` row in VS Code chat input area (GitHub flow is not yet ready there).
- Remove laggy close animation in text-selection popover; keep open motion/positioning behavior.
- Fetch branches when picker opens and cache empty; show loading state instead of false “No branches found”.
- Fix share-image export metadata rendering (theme background resolution, timestamp rendering, footer alignment).
- Scope MCP services status/toggles to active directory to avoid cross-project leakage.
- Improve long user-message clamp behavior (40% cap variant, hidden scrollbar, scroll shadows, expansion detection).
- Fix desktop `Check for Updates` menu handler; prevent duplicate checks; show clear success/error toasts.
- Stabilize long user-message scrolling behavior (follow-up hardening).
- Avoid premature web update failure on slower servers.
- Restore user message image previews + fullscreen gallery navigation payload.
- Repair desktop chat drag-and-drop image attachments when native drop coords are missing.
- Move GitHub issue linking entry into Add attachment menu.
- Align header context usage percentage visuals with context panel.
- Align `@` file search with active project in all runtimes.
- Route `@` file discovery through OpenCode SDK `find.files`; remove legacy `/api/fs/search` reliance.
- Make chat `@` mention behavior consistent with files-style behavior.
- Keep status-row todos in stable order after status changes; add compact status icons; replace noisy priority labels.

## Refactors / UX Consistency
- Simplify chat attachment model and remove project file picker path.
- Keep composer focused on `@` mention file flow.
- Use direct `Attach files` action in VS Code instead of attachment dropdown path.
- Unify issue/PR picker behavior between desktop and mobile overlays.

packages/vscode/webview/api/files.ts

@@ -35,21 +35,31 @@ export const createVSCodeFilesAPI = (): FilesAPI => ({
   },
 
   async search(payload: FileSearchQuery): Promise<FileSearchResult[]> {
-    const data = await sendBridgeMessage<{ files: Array<{ path: string; relativePath?: string }> }>('api:fs:search', {
-      directory: normalizePath(payload.directory),
-      query: payload.query,
-      limit: payload.maxResults,
-      includeHidden: payload.includeHidden,
-      respectGitignore: payload.respectGitignore,
-    });
+    const directory = normalizePath(payload.directory);
+    const params = new URLSearchParams();
+    if (directory) {
+      params.set('directory', directory);
+    }
+    params.set('query', payload.query);
+    params.set('dirs', 'false');
+    params.set('type', 'file');
+    if (typeof payload.maxResults === 'number' && Number.isFinite(payload.maxResults)) {
+      params.set('limit', String(payload.maxResults));
+    }
 
-    const files = Array.isArray(data?.files) ? data.files : [];
-    return files
-      .filter((file) => file && typeof file.path === 'string')
-      .map((file) => ({
-        path: normalizePath(file.path),
-        preview: file.relativePath ? [normalizePath(file.relativePath)] : undefined,
-      }));
+    const response = await fetch(`/api/find/file?${params.toString()}`);
+    if (!response.ok) {
+      const error = await response.json().catch(() => ({ error: response.statusText }));
+      throw new Error((error as { error?: string }).error || 'Failed to search files');
+    }
+
+    const result = (await response.json()) as string[];
+    const files = Array.isArray(result) ? result : [];
+
+    return files.map((relativePath) => ({
+      path: normalizePath(`${directory}/${relativePath}`),
+      preview: [normalizePath(relativePath)],
+    }));
   },
 
   async createDirectory(path: string): Promise<{ success: boolean; path: string }> {