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/providers/Providers.tsx

@@ -0,0 +1,30 @@
+'use client';
+
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
+import { useState, ReactNode } from 'react';
+import { Toaster } from 'sonner';
+import { ThemeProvider } from './ThemeProvider';
+
+export function Providers({ children }: { children: ReactNode }) {
+  const [queryClient] = useState(
+    () =>
+      new QueryClient({
+        defaultOptions: {
+          queries: {
+            staleTime: 3 * 1000, // 3 seconds for real-time feel
+            refetchOnWindowFocus: false,
+            retry: 2,
+          },
+        },
+      })
+  );
+
+  return (
+    <ThemeProvider>
+      <QueryClientProvider client={queryClient}>
+        {children}
+        <Toaster position="top-right" richColors closeButton />
+      </QueryClientProvider>
+    </ThemeProvider>
+  );
+}

components/providers/ThemeProvider.tsx

@@ -0,0 +1,77 @@
+'use client';
+
+import { createContext, useContext, useEffect, useState, ReactNode } from 'react';
+
+type Theme = 'light' | 'dark' | 'system';
+
+interface ThemeContextType {
+  theme: Theme;
+  setTheme: (theme: Theme) => void;
+  resolvedTheme: 'light' | 'dark';
+}
+
+const ThemeContext = createContext<ThemeContextType | undefined>(undefined);
+
+export function ThemeProvider({ children }: { children: ReactNode }) {
+  const [theme, setThemeState] = useState<Theme>('system');
+  const [resolvedTheme, setResolvedTheme] = useState<'light' | 'dark'>('light');
+  const [mounted, setMounted] = useState(false);
+
+  useEffect(() => {
+    setMounted(true);
+    const stored = localStorage.getItem('theme') as Theme | null;
+    if (stored) {
+      setThemeState(stored);
+    }
+  }, []);
+
+  useEffect(() => {
+    if (!mounted) return;
+
+    const root = document.documentElement;
+    const systemTheme = window.matchMedia('(prefers-color-scheme: dark)').matches
+      ? 'dark'
+      : 'light';
+    const effectiveTheme = theme === 'system' ? systemTheme : theme;
+
+    // Add transition disable class
+    root.classList.add('disable-transitions');
+
+    // Update theme
+    if (effectiveTheme === 'dark') {
+      root.classList.add('dark');
+    } else {
+      root.classList.remove('dark');
+    }
+
+    setResolvedTheme(effectiveTheme);
+
+    // Re-enable transitions after a frame
+    requestAnimationFrame(() => {
+      root.classList.remove('disable-transitions');
+    });
+  }, [theme, mounted]);
+
+  const setTheme = (newTheme: Theme) => {
+    setThemeState(newTheme);
+    localStorage.setItem('theme', newTheme);
+  };
+
+  if (!mounted) {
+    return <>{children}</>;
+  }
+
+  return (
+    <ThemeContext.Provider value={{ theme, setTheme, resolvedTheme }}>
+      {children}
+    </ThemeContext.Provider>
+  );
+}
+
+export function useTheme() {
+  const context = useContext(ThemeContext);
+  if (!context) {
+    throw new Error('useTheme must be used within ThemeProvider');
+  }
+  return context;
+}