Add CRUD endpoints for game levels with level field in response:
- GET /v1/wechat-game/levels - list all levels ordered by sort_order
- GET /v1/wechat-game/levels/:id - get single level by ID
New files:
- Level entity mapping to levels table
- LevelRepository with ordered query support
- LevelResponseDto with level field (1-based index from sort_order)
- Add deploy.sh script for automated deployment via rsync
- Add ecosystem.config.js for PM2 process management (2 instances)
- Add .env.production.example as production env template
- Update config.module.ts to support .env.production file
- Add 'pnpm run deploy' script to package.json
