Add healthcheck support to Dockerfile

- Install curl for health check compatibility
- Add built-in Docker healthcheck with proper timing
- Include start-period to allow server to initialize
- Fix Coolify deployment issues with health checks

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Dockerfile

@@ -19,8 +19,8 @@ RUN npm run build
 # Production stage - Use a simple server that works with Coolify
 FROM node:18-alpine AS production
 
-# Install serve package
-RUN npm install -g serve
+# Install curl and serve package
+RUN apk add --no-cache curl && npm install -g serve
 
 # Set working directory
 WORKDIR /app
@@ -39,5 +39,9 @@ USER nextjs
 # Expose port 3000 (Coolify default)
 EXPOSE 3000
 
+# Add healthcheck
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+  CMD curl -f http://localhost:3000/ || exit 1
+
 # Start the server
 CMD ["serve", "-s", "dist", "-l", "3000"]