feat: add Docker support with environment configuration and health checks

Dockerfile

@@ -0,0 +1,38 @@
+# Use Node.js 22 Alpine for smaller image size
+FROM node:22-alpine
+
+# Install pnpm globally
+RUN npm install -g pnpm@9.15.3
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files
+COPY package.json pnpm-lock.yaml ./
+
+# Install dependencies
+RUN pnpm install --frozen-lockfile
+
+# Copy source code
+COPY . .
+
+# Set default environment variables (can be overridden at runtime)
+# Navidrome configuration is optional - app will prompt if not provided
+ENV NEXT_PUBLIC_NAVIDROME_URL=""
+ENV NEXT_PUBLIC_NAVIDROME_USERNAME=""
+ENV NEXT_PUBLIC_NAVIDROME_PASSWORD=""
+ENV NEXT_PUBLIC_POSTHOG_KEY=""
+ENV NEXT_PUBLIC_POSTHOG_HOST=""
+ENV PORT=3000
+
+# Generate git commit hash for build info (fallback if not available)
+RUN echo "NEXT_PUBLIC_COMMIT_SHA=docker-build" > .env.local
+
+# Build the application
+RUN pnpm build
+
+# Expose the port
+EXPOSE $PORT
+
+# Start the application
+CMD ["sh", "-c", "pnpm start -p $PORT"]