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>

Dockerfile

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+# Stage 1: Dependencies
+FROM node:20-alpine AS deps
+RUN corepack enable && corepack prepare pnpm@latest --activate
+WORKDIR /app
+
+# Copy dependency files
+COPY package.json pnpm-lock.yaml ./
+
+# Install dependencies with frozen lockfile
+RUN pnpm install --frozen-lockfile
+
+# Stage 2: Builder
+FROM node:20-alpine AS builder
+RUN corepack enable && corepack prepare pnpm@latest --activate
+WORKDIR /app
+
+# Copy dependencies from deps stage
+COPY --from=deps /app/node_modules ./node_modules
+
+# Copy source code
+COPY . .
+
+# Build arguments for environment variables (optional defaults)
+ARG SUPERVISOR_HOST=localhost
+ARG SUPERVISOR_PORT=9001
+ARG SUPERVISOR_USERNAME=
+ARG SUPERVISOR_PASSWORD=
+
+# Set environment variables for production build
+ENV NEXT_TELEMETRY_DISABLED=1
+ENV NODE_ENV=production
+ENV SUPERVISOR_HOST=${SUPERVISOR_HOST}
+ENV SUPERVISOR_PORT=${SUPERVISOR_PORT}
+ENV SUPERVISOR_USERNAME=${SUPERVISOR_USERNAME}
+ENV SUPERVISOR_PASSWORD=${SUPERVISOR_PASSWORD}
+
+# Build the Next.js application
+RUN pnpm build
+
+# Stage 3: Production runner
+FROM node:20-alpine AS runner
+WORKDIR /app
+
+ENV NODE_ENV=production
+ENV NEXT_TELEMETRY_DISABLED=1
+
+# Create non-root user
+RUN addgroup --system --gid 1001 nodejs && \
+    adduser --system --uid 1001 nextjs
+
+# Copy necessary files from builder
+COPY --from=builder /app/public ./public
+COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
+
+# Switch to non-root user
+USER nextjs
+
+# Expose port
+EXPOSE 3000
+
+ENV PORT=3000
+ENV HOSTNAME="0.0.0.0"
+
+# Runtime environment variables (can be overridden at runtime)
+ENV SUPERVISOR_HOST=localhost
+ENV SUPERVISOR_PORT=9001
+ENV SUPERVISOR_USERNAME=
+ENV SUPERVISOR_PASSWORD=
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
+  CMD node -e "require('http').get('http://localhost:3000/api/health', (r) => {process.exit(r.statusCode === 200 ? 0 : 1)})"
+
+# Start the application
+CMD ["node", "server.js"]