fix(ui): address PR #644 review comments

Keyboard accessibility:
- Add role="button", tabIndex, onKeyDown, and aria-label to clickable divs
  in project-status-card, recent-activity-feed, and running-agents-panel

Bug fixes:
- Fix handleActivityClick to use projectPath instead of projectId for
  initializeProject and check result before navigating
- Fix error handling in use-multi-project-status to use data.error string
  directly instead of data.error?.message

Improvements:
- Use GitBranch icon instead of Folder for branch display in running-agents-panel
- Add error logging for failed project loads in overview.ts
- Use type import for FeatureLoader in projects/index.ts
- Add data-testid to mobile Overview button in dashboard-view
- Add locale options for consistent time formatting in overview-view

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/ui/src/hooks/use-multi-project-status.ts

@@ -64,7 +64,7 @@ async function fetchProjectsOverview(): Promise<MultiProjectOverview> {
   const data = await response.json();
 
   if (!data.success) {
-    throw new Error(data.error?.message || 'Failed to fetch project overview');
+    throw new Error(data.error || 'Failed to fetch project overview');
   }
 
   return {