chore: add project analysis doc, clean up legacy scripts, update docs

- Add comprehensive project analysis document (项目分析文档.md)
- Add Windows startup guide and batch script
- Replace legacy startup scripts with run_production.py (Waitress)
- Remove deprecated bat scripts and duplicate run files
- Update .env.example, README.md, and docs

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

.env.example

@@ -16,6 +16,9 @@ FLASK_ENV=development
 # 调试模式（开发环境开启，生产环境关闭）
 DEBUG=True
 
+# HTTP 端口（可选；仅 Waitress 生产 run_production.py 读取；开发 run_dev.py 固定 5002）
+# PORT=5000
+
 # ========================================
 # 数据库配置
 # ========================================