fix: F12 P2 follow-up — batch imports set departmentId, optimize getDescendantIds, enforce campus root invariant

apps/server/src/rooms/rooms.controller.ts

@@ -275,7 +275,8 @@ export class RoomsController {
         monthlyRate,
       });
     });
-    const result = await this.service.batchImport(rows);
+    const departmentId = req.headers?.['x-campus-id'] ? parseInt(String(req.headers['x-campus-id']), 10) || undefined : undefined;
+    const result = await this.service.batchImport(rows, departmentId);
     await this.logService.log({
       userId: req.user?.id,
       username: req.user?.username,

apps/server/src/rooms/rooms.service.ts

@@ -246,6 +246,7 @@ export class RoomsService {
       rentalCategory?: string;
       monthlyRate?: number;
     }[],
+    departmentId?: number,
   ) {
     let imported = 0;
     let skipped = 0;
@@ -270,6 +271,7 @@ export class RoomsService {
           roomType: row.roomType || parsed.roomType || undefined,
           rentalCategory: row.rentalCategory || undefined,
           monthlyRate: row.monthlyRate ?? undefined,
+          departmentId: departmentId ?? undefined,
         }),
       );
       imported++;