fix: apply code review fixes — double layout, SSE leaks, interval leak, conflict values

- App.tsx: remove double-wrapped MainLayout from /notifications route
- NotificationBell.tsx: decouple SSE from popover open state using ref
- useNotifications.ts: fix interval leak in onerror via ref in cleanup
- notifications.controller.ts: unsubscribe on req.on('close') for SSE Subject
- schedules.controller.ts: use existing schedule values in conflict catch

apps/server/src/notifications/notifications.controller.ts

@@ -48,6 +48,9 @@ export class NotificationsController {
   @Sse('stream')
   stream(@Req() req: AuthenticatedRequest): Observable<MessageEvent> {
     const userId = req.user.id;
+    req.on('close', () => {
+      this.service.unsubscribe(userId);
+    });
     return this.service.subscribe(userId).pipe(
       map((notification) => ({
         data: JSON.stringify({

apps/server/src/schedules/schedules.controller.ts

@@ -108,6 +108,7 @@ export class SchedulesController {
     @Request() req: { user?: { id: number; username: string }; headers?: Record<string, string> },
   ) {
     const { ipAddress, userAgent } = extractRequestInfo(req);
+    const existing = await this.service.findOne(+id);
     try {
       const result = await this.service.update(+id, dto);
       await this.logService.log({
@@ -126,7 +127,7 @@ export class SchedulesController {
       if (error instanceof ConflictException) {
         try {
           const conflicts = await this.service.checkConflict(
-            dto.classroomId ?? 0, dto.weekDay ?? 0, dto.startTime ?? '', dto.endTime ?? '', dto.startDate ?? '', dto.endDate ?? '',
+            existing.classroomId, existing.weekDay, existing.startTime, existing.endTime, existing.startDate, existing.endDate,
           );
           const teacherIds = [...new Set(conflicts.map(c => c.teacherId).filter(Boolean))];
           if (teacherIds.length > 0) {
@@ -134,7 +135,7 @@ export class SchedulesController {
               recipientIds: teacherIds,
               type: NotificationType.SCHEDULE_CONFLICT,
               title: '排课冲突',
-              content: `教室${dto.classroomId} 周${dto.weekDay} ${dto.startTime}-${dto.endTime} (更新) 与已有排课冲突`,
+              content: `教室${existing.classroomId} 周${existing.weekDay} ${existing.startTime}-${existing.endTime} (更新) 与已有排课冲突`,
             });
           }
         } catch {}