Task 4: 学生列表 tenantId 筛选生效

- StudentsService.findAll() 接收 tenantId 参数并按 tenantId 过滤
- StudentsController.findAll() 增加 tenantId 查询参数
- students.organization 列仍在 occupancy/room-visual/import 等场景使用，未删除列

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

@@ -43,8 +43,14 @@ export class StudentsController {
     @Query('name') name?: string,
     @Query('status') status?: string,
     @Query('includeArchived') includeArchived?: string,
+    @Query('tenantId') tenantId?: string,
   ) {
-    return this.service.findAll({ name, status, includeArchived: includeArchived === 'true' });
+    return this.service.findAll({
+      name,
+      status,
+      includeArchived: includeArchived === 'true',
+      tenantId: tenantId ? +tenantId : undefined,
+    });
   }
 
   @Get('export')