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>

lib/utils/cn.ts

@@ -0,0 +1,10 @@
+import { clsx, type ClassValue } from 'clsx';
+import { twMerge } from 'tailwind-merge';
+
+/**
+ * Utility function to merge class names with Tailwind CSS classes
+ * Combines clsx for conditional classes and tailwind-merge for deduplication
+ */
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}