Develop (#55)

feat: optimize dashboard/search UX and simplify extension architecture

Redesign Dashboard with compact tool grid and recently used tools
Improve TopBar search UX with Cmd/Ctrl+K shortcut and better history navigation
Reorganize project structure into src/
Migrate i18n from react-i18next to chrome.i18n
Remove runtime language switch and settings page
Remove HTML/Markdown conversion tools
Clean up unused code, dead animations, redundant comments, and imports
Improve component consistency with shadcn/ui patterns
Replace hardcoded strings/colors with i18n tokens and theme tokens
Add comprehensive project documentation and coding standards
Fix CI artifact upload workflow and multiple TypeScript/test issues

Includes various refactors, UI polish, i18n cleanup, CI improvements,
and maintenance updates across the codebase.

src/entrypoints/popup/App.tsx

@@ -0,0 +1,43 @@
+import RouterProvider from '@/providers/RouterProvider';
+import TopBar from '@/components/TopBar';
+import RouterContainer from '@/components/RouterContainer';
+import ErrorBoundary from '@/components/ErrorBoundary';
+import { SnackbarProvider } from '@/components/GlobalSnackbar';
+import { getEntryPointType } from '@/config/features';
+import { useMemo } from 'react';
+
+export default function App() {
+  const entryType = useMemo(() => getEntryPointType(), []);
+
+  const routerConfig = useMemo(() => {
+    if (entryType === 'tab') {
+      return {
+        syncKey: 'app/tabRoute' as const,
+        visiblePagesKey: 'app/tabVisiblePages' as const,
+        pageOrderKey: 'app/tabPageOrder' as const,
+      };
+    }
+    return {
+      syncKey: 'app/popupRoute' as const,
+      visiblePagesKey: 'app/popupVisiblePages' as const,
+      pageOrderKey: 'app/popupPageOrder' as const,
+    };
+  }, [entryType]);
+
+  return (
+    <RouterProvider
+      syncKey={routerConfig.syncKey}
+      visiblePagesKey={routerConfig.visiblePagesKey}
+      pageOrderKey={routerConfig.pageOrderKey}
+    >
+      <SnackbarProvider initialOptions={{ autoHideDuration: 1500 }}>
+        <div className="app flex flex-col w-[400px] max-w-[400px] min-w-[400px] h-[600px] min-h-[600px] overflow-hidden bg-background sm:w-screen sm:max-w-none sm:min-w-0 sm:h-screen sm:min-h-0">
+          <TopBar />
+          <ErrorBoundary>
+            <RouterContainer />
+          </ErrorBoundary>
+        </div>
+      </SnackbarProvider>
+    </RouterProvider>
+  );
+}