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/components/ui/label.tsx

@@ -0,0 +1,19 @@
+import * as React from 'react';
+import * as LabelPrimitive from '@radix-ui/react-label';
+import { cva, type VariantProps } from 'class-variance-authority';
+
+import { cn } from '@/lib/utils';
+
+const labelVariants = cva(
+  'text-sm font-medium leading-none peer-disabled:cursor-not-allowed peer-disabled:opacity-70',
+);
+
+const Label = React.forwardRef<
+  React.ElementRef<typeof LabelPrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof LabelPrimitive.Root> & VariantProps<typeof labelVariants>
+>(({ className, ...props }, ref) => (
+  <LabelPrimitive.Root ref={ref} className={cn(labelVariants(), className)} {...props} />
+));
+Label.displayName = LabelPrimitive.Root.displayName;
+
+export { Label };