Enhance backend startup logging and API endpoint display

- Updated `run.py` to conditionally print startup information only in the reloader process to avoid duplicate logs in debug mode.
- Modified `__init__.py` to log startup and completion messages based on the reloader process condition.
- Added warnings suppression in `graph_builder.py` for Pydantic v2 regarding Field usage.
- Revised `ontology_generator.py` to enforce strict design guidelines for entity types and relationships, ensuring compliance with new requirements.
- Improved logging behavior in `logger.py` to prevent log propagation to the root logger, avoiding duplicate outputs.

backend/run.py

@@ -31,22 +31,26 @@ def main():
     port = int(os.environ.get('FLASK_PORT', 5001))
     debug = Config.DEBUG
     
-    print(f"""
+    # 只在 reloader 子进程中打印启动信息（避免 debug 模式下打印两次）
+    # WERKZEUG_RUN_MAIN=true 表示当前是 reloader 启动的子进程
+    is_reloader_process = os.environ.get('WERKZEUG_RUN_MAIN') == 'true'
+    if not debug or is_reloader_process:
+        print(f"""
 ╔══════════════════════════════════════════════════╗
 ║           MiroFish Backend Server                ║
 ╠══════════════════════════════════════════════════╣
-║  Running on: http://{host}:{port}
-║  Debug mode: {debug}
-║  
-║  API Endpoints:
-║    POST /api/graph/ontology/generate  - 生成本体
-║    POST /api/graph/build              - 构建图谱
-║    GET  /api/graph/task/<task_id>     - 查询任务
-║    GET  /api/graph/tasks              - 列出任务
-║    GET  /api/graph/data/<graph_id>    - 获取图数据
-║    DELETE /api/graph/delete/<graph_id>- 删除图谱
+║  Running on: http://{host}:{port}                ║
+║  Debug mode: {debug}                             ║
+║                                                  ║
+║  API Endpoints:                                  ║
+║    POST /api/graph/ontology/generate  - 生成本体  ║
+║    POST /api/graph/build              - 构建图谱  ║
+║    GET  /api/graph/task/<task_id>     - 查询任务  ║
+║    GET  /api/graph/tasks              - 列出任务  ║
+║    GET  /api/graph/data/<graph_id>    - 获取图数据║
+║    DELETE /api/graph/delete/<graph_id>- 删除图谱  ║
 ╚══════════════════════════════════════════════════╝
-    """)
+        """)
     
     # 启动服务
     app.run(host=host, port=port, debug=debug, threaded=True)