fix: audit remediation — SSE user scoping, FK transactional safety, UI error handling

- H4: scoped SSE import progress to exact userId match; non-HTTP events excluded from all subscribers
- H2: moved PRAGMA foreign_key_check inside SQLite transaction before COMMIT; violations rollback preserving old tables
- M1: removed dead axios-style error branch from extractErrorMessage (interceptor already unwraps)
- M2: split handleSave try/catch — save errors vs reload errors shown distinctly
- M3: added provider field validation before AI config test request
- Added SSE scoping regression tests (import service + controller)
- Added FK check failure rollback test (database-migrations.spec)
- Updated controller spec expectations for userId parameter

Co-authored-by: Code Review <branch-review>

apps/admin/src/App.tsx

@@ -193,7 +193,7 @@ const App: React.FC = () => {
               <Route
                 path="teachers"
                 element={
-                  <PermissionRoute permission="user:view">
+                  <PermissionRoute permission="teacher:view">
                     <TeachersPage />
                   </PermissionRoute>
                 }
@@ -252,7 +252,7 @@ const App: React.FC = () => {
               <Route
                 path="teacher-workspace"
                 element={
-                  <PermissionRoute permission="class:view">
+                  <PermissionRoute permission="teacher-workspace:view">
                     <TeacherWorkspacePage />
                   </PermissionRoute>
                 }