feat: initial commit - Supervisor UI with Next.js 16 and Tailwind CSS 4

- Modern web interface for Supervisor process management
- Built with Next.js 16 (App Router) and Tailwind CSS 4
- Full XML-RPC client implementation for Supervisor API
- Real-time process monitoring with auto-refresh
- Process control: start, stop, restart operations
- Modern dashboard with system status and statistics
- Dark/light theme with OKLCH color system
- Docker multi-stage build with runtime env var configuration
- Gitea CI/CD workflow for automated builds
- Comprehensive documentation (README, IMPLEMENTATION, DEPLOYMENT)

Features:
- Backend proxy pattern for secure API communication
- React Query for state management and caching
- TypeScript strict mode with Zod validation
- Responsive design with mobile support
- Health check endpoint for monitoring
- Non-root user security in Docker

Environment Variables:
- SUPERVISOR_HOST, SUPERVISOR_PORT
- SUPERVISOR_USERNAME, SUPERVISOR_PASSWORD (optional)
- Configurable at build-time and runtime

🤖 Generated with Claude Code (https://claude.com/claude-code)

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

components/ui/card.tsx

@@ -0,0 +1,69 @@
+import { HTMLAttributes, forwardRef } from 'react';
+import { cn } from '@/lib/utils/cn';
+
+const Card = forwardRef<HTMLDivElement, HTMLAttributes<HTMLDivElement>>(
+  ({ className, ...props }, ref) => (
+    <div
+      ref={ref}
+      className={cn(
+        'rounded-lg border bg-card text-card-foreground shadow-sm',
+        className
+      )}
+      {...props}
+    />
+  )
+);
+Card.displayName = 'Card';
+
+const CardHeader = forwardRef<HTMLDivElement, HTMLAttributes<HTMLDivElement>>(
+  ({ className, ...props }, ref) => (
+    <div
+      ref={ref}
+      className={cn('flex flex-col space-y-1.5 p-6', className)}
+      {...props}
+    />
+  )
+);
+CardHeader.displayName = 'CardHeader';
+
+const CardTitle = forwardRef<HTMLParagraphElement, HTMLAttributes<HTMLHeadingElement>>(
+  ({ className, ...props }, ref) => (
+    <h3
+      ref={ref}
+      className={cn('text-2xl font-semibold leading-none tracking-tight', className)}
+      {...props}
+    />
+  )
+);
+CardTitle.displayName = 'CardTitle';
+
+const CardDescription = forwardRef<HTMLParagraphElement, HTMLAttributes<HTMLParagraphElement>>(
+  ({ className, ...props }, ref) => (
+    <p
+      ref={ref}
+      className={cn('text-sm text-muted-foreground', className)}
+      {...props}
+    />
+  )
+);
+CardDescription.displayName = 'CardDescription';
+
+const CardContent = forwardRef<HTMLDivElement, HTMLAttributes<HTMLDivElement>>(
+  ({ className, ...props }, ref) => (
+    <div ref={ref} className={cn('p-6 pt-0', className)} {...props} />
+  )
+);
+CardContent.displayName = 'CardContent';
+
+const CardFooter = forwardRef<HTMLDivElement, HTMLAttributes<HTMLDivElement>>(
+  ({ className, ...props }, ref) => (
+    <div
+      ref={ref}
+      className={cn('flex items-center p-6 pt-0', className)}
+      {...props}
+    />
+  )
+);
+CardFooter.displayName = 'CardFooter';
+
+export { Card, CardHeader, CardFooter, CardTitle, CardDescription, CardContent };