feat(backend): 添加 Groq供应商支持并优化笔记生成流程- 在 builtin_providers.json 中添加 Groq 供应商信息

- 实现 GroqTranscriber 类以支持 Groq 语音转录服务
- 新增异常处理中间件以提高系统稳定性
- 优化笔记生成流程，增加错误处理和日志记录
- 添加思维导图功能和相关组件
-重构 Markdown 查看器以支持切换视图模式

backend/app/core/exception_handlers.py

@@ -0,0 +1,38 @@
+# app/core/exception_handlers.py
+from fastapi import Request, HTTPException
+from fastapi.exceptions import RequestValidationError
+from fastapi.responses import JSONResponse
+
+from app.utils.logger import get_logger
+from app.utils.response import ResponseWrapper
+from app.utils.status_code import StatusCode
+logger = get_logger(__name__)
+
+def register_exception_handlers(app):
+    @app.exception_handler(RequestValidationError)
+    async def validation_exception_handler(request: Request, exc: RequestValidationError):
+        errors = []
+        for err in exc.errors():
+            loc = err.get("loc", [])
+            field = loc[-1] if loc else "body"
+            msg = err.get("msg", "参数不合法")
+            errors.append({"field": field, "error": msg})
+        return JSONResponse(
+            status_code=400,
+            content=ResponseWrapper.error(msg="参数验证失败", code=StatusCode.PARAM_ERROR, data=errors)
+        )
+
+    @app.exception_handler(HTTPException)
+    async def http_exception_handler(request: Request, exc: HTTPException):
+        return JSONResponse(
+            status_code=exc.status_code,
+            content=ResponseWrapper.error(msg=str(exc.detail), code=StatusCode.FAIL)
+        )
+
+    @app.exception_handler(Exception)
+    async def global_exception_handler(request: Request, exc: Exception):
+        logger.exception(f"服务器内部错误: {exc}")
+        return JSONResponse(
+            status_code=500,
+            content=ResponseWrapper.error(msg="服务器内部错误", code=StatusCode.FAIL, data=str(exc))
+        )