权限管理：接入项目级权限矩阵

新增项目级角色权限矩阵，覆盖 PM、CRA、PV、IMP、QA 等项目角色，并通过迁移表持久化各业务模块的读写权限。

后端将参与者、合同费用、物资、启动、里程碑、风险问题、监查稽查、FAQ、共享库、文件版本等接口接入矩阵校验，修复审计日志导出权限和登录 502 的依赖导入问题。

前端新增权限管理页面和项目路由权限映射，按矩阵控制导航显示、直接访问拦截、操作按钮启停，并限制管理后台仅 admin 和授权 PM 可进入。

补充后端权限归一化与接口静态测试、前端路由/权限工具/权限管理页面/工作台等回归测试。

backend/app/api/v1/visits.py

@@ -3,7 +3,7 @@ import uuid
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.core.deps import get_current_user, get_db_session, require_study_member, require_study_roles, require_study_not_locked
+from app.core.deps import get_current_user, get_db_session, require_study_not_locked, require_study_permission
 from app.crud import audit as audit_crud
 from app.crud import site as site_crud
 from app.crud import subject as subject_crud
@@ -33,7 +33,7 @@ async def _ensure_subject_active(db: AsyncSession, subject) -> None:
 @router.get(
     "/",
     response_model=list[VisitRead],
-    dependencies=[Depends(require_study_member())],
+    dependencies=[Depends(require_study_permission("subjects", "read"))],
 )
 async def list_visits(
     study_id: uuid.UUID,
@@ -50,7 +50,7 @@ async def list_visits(
     "/",
     response_model=VisitRead,
     status_code=status.HTTP_201_CREATED,
-    dependencies=[Depends(require_study_roles(["PM", "CRA"])), Depends(require_study_not_locked())],
+    dependencies=[Depends(require_study_permission("subjects", "write")), Depends(require_study_not_locked())],
 )
 async def create_visit(
     study_id: uuid.UUID,
@@ -115,7 +115,7 @@ async def create_visit(
     "/early-termination",
     response_model=VisitRead,
     status_code=status.HTTP_201_CREATED,
-    dependencies=[Depends(require_study_roles(["PM", "CRA"])), Depends(require_study_not_locked())],
+    dependencies=[Depends(require_study_permission("subjects", "write")), Depends(require_study_not_locked())],
 )
 async def create_early_termination(
     study_id: uuid.UUID,
@@ -168,7 +168,7 @@ async def create_early_termination(
 @router.patch(
     "/{visit_id}",
     response_model=VisitRead,
-    dependencies=[Depends(require_study_roles(["PM", "CRA"])), Depends(require_study_not_locked())],
+    dependencies=[Depends(require_study_permission("subjects", "write")), Depends(require_study_not_locked())],
 )
 async def update_visit(
     study_id: uuid.UUID,
@@ -211,7 +211,7 @@ async def update_visit(
 @router.delete(
     "/{visit_id}",
     status_code=status.HTTP_204_NO_CONTENT,
-    dependencies=[Depends(require_study_roles(["PM", "CRA"])), Depends(require_study_not_locked())],
+    dependencies=[Depends(require_study_permission("subjects", "write")), Depends(require_study_not_locked())],
 )
 async def delete_visit(
     study_id: uuid.UUID,