feat(docs): enhance README and backend documentation for new user onboarding and backend conventions

- Added a "Start Here" section in both English and Chinese README files to guide new users on running the project locally and exploring its features.
- Introduced backend conventions for date and serialization handling, clarifying the use of Pydantic v2 and PostgreSQL.
- Updated the "Quick Start" section with detailed steps for first-time local setup, including environment requirements and backend setup instructions.
- Improved overall structure and clarity of documentation to facilitate better understanding for developers and contributors.

backend/app/api/v1/module_system/params/service.py

@@ -166,12 +166,14 @@ class ParamsService:
         new_obj = await ParamsCRUD(auth).update_obj_crud(id=id, data=data)
         if not new_obj:
             raise CustomException(msg="更新失败，系统配置不存在")
-        new_obj_dict = ParamsOutSchema.model_validate(new_obj).model_dump()
+        out = ParamsOutSchema.model_validate(new_obj)
+        new_obj_dict = out.model_dump()
+        redis_payload = out.model_dump(mode="json")
 
         # 同步redis
         redis_key = f"{RedisInitKeyConfig.SYSTEM_CONFIG.key}:{new_obj.config_key}"
         try:
-            value = json.dumps(new_obj_dict, ensure_ascii=False)
+            value = json.dumps(redis_payload, ensure_ascii=False)
             result = await RedisCURD(redis).set(
                 key=redis_key,
                 value=value,
@@ -306,8 +308,10 @@ class ParamsService:
                     # 保存到Redis并设置过期时间
                     for config in config_obj:
                         redis_key = f"{RedisInitKeyConfig.SYSTEM_CONFIG.key}:{config.config_key}"
-                        config_obj_dict = ParamsOutSchema.model_validate(config).model_dump()
-                        value = json.dumps(config_obj_dict, ensure_ascii=False)
+                        out = ParamsOutSchema.model_validate(config)
+                        config_obj_dict = out.model_dump()
+                        redis_payload = out.model_dump(mode="json")
+                        value = json.dumps(redis_payload, ensure_ascii=False)
                         result = await RedisCURD(redis).set(
                             key=redis_key,
                             value=value,