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/server/src/students/students.controller.ts

@@ -52,6 +52,12 @@ export class StudentsController {
     );
   }
 
+  @Get('basic-lookups')
+  @RequirePermission('student:basic-view', 'student:view')
+  getBasicLookups() {
+    return this.service.getBasicLookups();
+  }
+
   @Get()
   @RequirePermission('student:view')
   async findAll(