Update Dockerfile for Next.js 15 migration with production-optimized build:
- Multi-stage build separating compilation from runtime
- Next.js standalone output mode (~150-200MB final image)
- Non-root user (nextjs:1000) for security hardening
- Health check endpoint for orchestration monitoring
- Node.js 20 Alpine runtime for minimal footprint
Add .dockerignore to exclude development files from build context,
reducing build time and image size.
Update README with comprehensive Docker deployment documentation including
environment variable configuration and image features.
OpenSpec: Implements fix-dockerfile-nextjs proposal (26/30 tasks completed)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
