feat: Add Docker containerization for consistent deployment

- Multi-stage Dockerfile with Node.js 20 Alpine base
- Production and development docker-compose configurations
- Health check API endpoint for container monitoring
- Build and deployment scripts with versioning support
- Port 3000 configuration for nginx compatibility
- Non-root user and security hardening
- Resource limits and logging configuration
- Package.json scripts for Docker operations

This eliminates dependency conflicts and provides reproducible deployments.

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

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

.dockerignore

@@ -0,0 +1,81 @@
+# Dependencies
+node_modules/
+.npm
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+
+# Development files
+.env.local
+.env.development.local
+.env.test.local
+*.local
+
+# Build outputs (will be created during Docker build)
+dist/
+build/
+.astro/
+
+# Version control
+.git/
+.gitignore
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Logs (will be mounted as volume)
+logs/
+*.log
+
+# Test files
+coverage/
+*.lcov
+.nyc_output/
+
+# Cache
+.eslintcache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Documentation
+docs/
+README.md
+*.md
+!CLAUDE.md
+
+# Docker files (prevent recursion)
+Dockerfile*
+docker-compose*.yml
+.dockerignore
+
+# Development scripts
+scripts/
+test-*.js
+test-*.mjs
+
+# Backup files
+*.backup
+*_backup.*
+
+# Style guide and design files
+styleGuide/
+*.pdf
+*.jpg
+*.png
+cookies.txt