docs: add comprehensive documentation

- Add README.md with project overview, features, quick start guide,
  project structure, environment variables, and scripts
- Add docs/API.md with complete API reference for all endpoints
- Add docs/DEPLOYMENT.md with production deployment guide covering
  PM2, Nginx, SSL, and Docker options
- Add docker-compose.yml for containerized deployment
- Add Dockerfile with multi-stage build for optimized production image
- Add .dockerignore for efficient Docker builds

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

.dockerignore

@@ -0,0 +1,44 @@
+# Dependencies
+node_modules
+**/node_modules
+
+# Build outputs
+.next
+**/dist
+**/.turbo
+
+# Development files
+.env
+.env.local
+.env.*.local
+*.log
+npm-debug.log*
+
+# IDE
+.vscode
+.idea
+*.swp
+*.swo
+
+# Git
+.git
+.gitignore
+
+# Docker
+Dockerfile
+docker-compose*.yml
+.dockerignore
+
+# Documentation (not needed in image)
+docs
+*.md
+!README.md
+
+# Tests
+**/*.test.*
+**/*.spec.*
+coverage
+
+# Misc
+.DS_Store
+Thumbs.db