feat(AIChatPanel): add aria-labels for accessibility; clean up unused lines

feat(AppShell): improve token storage message styling for better visibility
feat(ProjectDetail): implement skeleton loading state for project details
fix(ProjectSidebar): refactor variable declaration for clarity
style(PriorityBadge): enhance priority badge colors for better contrast
refactor(TaskRow): simplify className handling with utility function
fix(TasksPage): replace loader icon with clock icon for in-progress tasks
feat(TimelinePage): enhance empty state with descriptive messaging and icon

src/renderer/components/projects/ProjectDetail.tsx

@@ -4,6 +4,7 @@ import { format } from 'date-fns';
 import { useNavigate } from '@tanstack/react-router';
 import { trpc } from '@/lib/trpc';
 import { Button } from '@/components/ui/button';
+import { Skeleton } from '@/components/ui/skeleton';
 import { Item, ItemMedia, ItemContent, ItemTitle, ItemDescription } from '@/components/ui/item';
 import {
   Breadcrumb,
@@ -167,8 +168,17 @@ export function ProjectDetail({ projectId }: ProjectDetailProps) {
 
   if (isLoading) {
     return (
-      <div className="flex items-center justify-center h-full text-sm text-muted-foreground">
-        Loading project...
+      <div className="p-6 flex flex-col gap-6">
+        <div className="flex flex-col gap-1">
+          <Skeleton className="h-4 w-24" />
+          <Skeleton className="h-8 w-56" />
+        </div>
+        <div className="grid grid-cols-3 gap-4">
+          <Skeleton className="h-20 rounded-lg" />
+          <Skeleton className="h-20 rounded-lg" />
+          <Skeleton className="h-20 rounded-lg" />
+        </div>
+        <Skeleton className="h-16 rounded-lg" />
       </div>
     );
   }