feat: add Docker deployment support

- Multi-stage Dockerfile (Node build + Go build + Alpine runtime)
- docker-compose.yml with named volume for data persistence
- In-container Nginx reverse proxy (static files + API)
- Entrypoint script for graceful process management
- .dockerignore for optimized build context
- Updated README (zh/en) with Docker quick start and deployment docs

Closes #14

.dockerignore

@@ -0,0 +1,26 @@
+# Dependencies
+web/node_modules/
+
+# Build artifacts
+server/bin/
+web/dist/
+
+# Data & logs
+data/
+*.db
+*.log
+
+# IDE & OS
+.idea/
+.vscode/
+*.swp
+*.swo
+.DS_Store
+
+# Git
+.git/
+.github/
+
+# Docker
+Dockerfile
+docker-compose*.yml