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/ui/src/stores/useFileSearchStore.ts

@@ -19,7 +19,7 @@ interface FileSearchStoreState {
     directory: string,
     query: string,
     limit?: number,
-    options?: { includeHidden?: boolean; respectGitignore?: boolean }
+    options?: { includeHidden?: boolean; respectGitignore?: boolean; type?: 'file' | 'directory' }
   ) => Promise<ProjectFileSearchHit[]>;
   invalidateDirectory: (directory?: string | null) => void;
 }
@@ -29,11 +29,12 @@ const buildCacheKey = (
   query: string,
   limit: number,
   includeHidden: boolean,
-  respectGitignore: boolean
+  respectGitignore: boolean,
+  type: 'file' | 'directory'
 ) => {
   const normalizedDirectory = directory.trim();
   const normalizedQuery = query.trim().toLowerCase();
-  return `${normalizedDirectory}::${normalizedQuery}::${limit}::${includeHidden ? '1' : '0'}::${respectGitignore ? '1' : '0'}`;
+  return `${normalizedDirectory}::${normalizedQuery}::${limit}::${includeHidden ? '1' : '0'}::${respectGitignore ? '1' : '0'}::${type}`;
 };
 
 export const useFileSearchStore = create<FileSearchStoreState>()(
@@ -51,7 +52,8 @@ export const useFileSearchStore = create<FileSearchStoreState>()(
         const normalizedQuery = typeof query === 'string' ? query.trim() : '';
         const includeHidden = Boolean(options?.includeHidden);
         const respectGitignore = options?.respectGitignore ?? true;
-        const key = buildCacheKey(normalizedDirectory, normalizedQuery, limit, includeHidden, respectGitignore);
+        const type = options?.type === 'directory' ? 'directory' : 'file';
+        const key = buildCacheKey(normalizedDirectory, normalizedQuery, limit, includeHidden, respectGitignore, type);
         const now = Date.now();
         const cached = get().cache[key];
 
@@ -70,6 +72,8 @@ export const useFileSearchStore = create<FileSearchStoreState>()(
             limit,
             includeHidden,
             respectGitignore,
+            dirs: type !== 'file',
+            type,
           })
           .then((files) => {
             set((state) => {