chore: 清理仓库废弃代码和临时文件

删除文件:
- 根目录: package.json, package-lock.json, .DS_Store
- 后端未使用模块: token_manager_example.py, kling_dto.py, crud/avatar.py
- 未注册路由: ai_models.py, klingai.py, qiniu.py, video.py
- 废弃配置: docker-compose.dev.yml
- 前端未使用页面: AudioMixing.tsx/css, VideoEditing.tsx/css
- 所有 .DS_Store 临时文件

新增: .gitignore（忽略 .DS_Store, node_modules, __pycache__ 等）

清理后减少 ~2700+ 行无效代码

python-api/docker-compose.dev.yml

@@ -1,105 +0,0 @@
-# 美家卡智剪 - 开发服务器配置
-# 自包含：PostgreSQL + Redis + API + Scheduler
-# usage: docker compose -f docker-compose.dev.yml up -d --build
-
-version: "3.8"
-
-services:
-  db:
-    image: postgres:15-alpine
-    container_name: meijiaka-dev-db
-    environment:
-      POSTGRES_USER: postgres
-      POSTGRES_PASSWORD: postgres
-      POSTGRES_DB: meijiaka_dev
-    volumes:
-      - postgres_dev_data:/var/lib/postgresql/data
-    ports:
-      - "127.0.0.1:5432:5432"
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U postgres"]
-      interval: 5s
-      timeout: 5s
-      retries: 5
-    networks:
-      - dev-network
-
-  redis:
-    image: redis:7-alpine
-    container_name: meijiaka-dev-redis
-    volumes:
-      - redis_dev_data:/data
-    ports:
-      - "127.0.0.1:6379:6379"
-    healthcheck:
-      test: ["CMD", "redis-cli", "ping"]
-      interval: 5s
-      timeout: 5s
-      retries: 5
-    networks:
-      - dev-network
-
-  api:
-    build:
-      context: .
-      dockerfile: Dockerfile
-    container_name: meijiaka-dev-api
-    environment:
-      - ENV=development
-      - DEBUG=true
-      - DATABASE_URL=postgresql+asyncpg://postgres:postgres@db:5432/meijiaka_dev
-      - REDIS_HOST=redis
-      - REDIS_PORT=6379
-      - REDIS_DB=0
-      - SECRET_KEY=dev-secret-key-do-not-use-in-prod
-      - MINIMAX_API_KEY=${MINIMAX_API_KEY}
-      - MINIMAX_BASE_URL=${MINIMAX_BASE_URL:-https://api.minimaxi.com}
-      - VIDU_API_KEY=${VIDU_API_KEY}
-      - VIDU_BASE_URL=${VIDU_BASE_URL:-https://api.vidu.cn}
-      - LOG_LEVEL=DEBUG
-    volumes:
-      - .:/app
-      - ../data:/root/Documents/Meijiaka-zj
-    ports:
-      - "8080:8000"
-    command: gunicorn app.main:app -w 1 -k uvicorn.workers.UvicornWorker --bind 0.0.0.0:8000 --reload
-    depends_on:
-      db:
-        condition: service_healthy
-      redis:
-        condition: service_healthy
-    networks:
-      - dev-network
-
-  scheduler:
-    build:
-      context: .
-      dockerfile: Dockerfile
-    container_name: meijiaka-dev-scheduler
-    environment:
-      - ENV=development
-      - DEBUG=true
-      - DATABASE_URL=postgresql+asyncpg://postgres:postgres@db:5432/meijiaka_dev
-      - REDIS_HOST=redis
-      - REDIS_PORT=6379
-      - REDIS_DB=0
-      - SECRET_KEY=dev-secret-key-do-not-use-in-prod
-    volumes:
-      - .:/app
-      - ../data:/root/Documents/Meijiaka-zj
-    command: python -m app.scheduler.main
-    depends_on:
-      db:
-        condition: service_healthy
-      redis:
-        condition: service_healthy
-    networks:
-      - dev-network
-
-volumes:
-  postgres_dev_data:
-  redis_dev_data:
-
-networks:
-  dev-network:
-    driver: bridge