chore: 添加项目配置文件

- 添加 Python 项目配置 (pyproject.toml)
- 添加环境变量示例 (.env.example)
- 添加 Docker 忽略文件 (.dockerignore)
- 添加 TypeScript 配置 (tsconfig.json, tsconfig.node.json)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/.dockerignore

@@ -0,0 +1,50 @@
+# Git
+.git
+.gitignore
+
+# Python
+__pycache__
+*.py[cod]
+*$py.class
+*.so
+.Python
+venv/
+.venv/
+env/
+.env
+*.egg-info/
+dist/
+build/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# Testing
+.pytest_cache/
+.coverage
+htmlcov/
+
+# Logs
+*.log
+logs/
+
+# Database
+*.db
+*.sqlite
+*.sqlite3
+
+# Uploads (should be persisted separately)
+uploads/*
+!uploads/.gitkeep
+
+# Docker
+Dockerfile
+.dockerignore
+
+# Misc
+.DS_Store
+*.md
+docs/