Add Docker deployment setup with health check endpoint

- Add multi-stage Dockerfile with standalone Next.js output
- Add docker-compose.yml with Caddy reverse proxy
- Add nginx configs for local and SSL setups
- Add Caddyfile for automatic HTTPS
- Add docker-entrypoint.sh for runtime config
- Add .env.example and .dockerignore
- Add comprehensive Docker README
- Add /api/health endpoint for container health checks
- Configure next.config.ts for standalone output

docker/.dockerignore

@@ -0,0 +1,96 @@
+# Dependencies
+node_modules
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+package-lock.json
+yarn.lock
+pnpm-lock.yaml
+
+# Build outputs
+.next
+out
+dist
+build
+*.tsbuildinfo
+
+# Environment files (these are passed via docker-compose)
+.env
+.env.local
+.env.*.local
+.env.dev
+.env.test
+.env.production
+
+# Version control
+.git
+.gitignore
+.gitattributes
+
+# IDE and editor files
+.vscode
+.idea
+*.swp
+*.swo
+*~
+.DS_Store
+Thumbs.db
+
+# Testing
+coverage
+.nyc_output
+*.test.ts
+*.test.tsx
+*.spec.ts
+*.spec.tsx
+tests
+test
+__tests__
+
+# Documentation (not needed in production image)
+*.md
+!README.md
+LICENSE
+CHANGELOG.md
+CONTRIBUTING.md
+
+# Docker files (avoid recursive copy)
+docker
+docker-compose*.yml
+Dockerfile*
+.dockerignore
+
+# CI/CD
+.github
+.gitlab-ci.yml
+.travis.yml
+azure-pipelines.yml
+Jenkinsfile
+
+# Logs
+logs
+*.log
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Misc
+.cache
+temp
+tmp
+.tmp
+uploads/*
+!uploads/.gitkeep
+
+# Large binary files
+*.mp4
+*.mov
+*.avi
+*.mkv
+*.pdf
+*.zip
+*.tar.gz
+*.rar