feat: add notification category filters

src/modules/notifications/notifications.service.spec.ts

@@ -107,6 +107,80 @@ describe('NotificationsService', () => {
     expect(notificationsRepository.countUnread).toHaveBeenCalledWith('507f1f77bcf86cd799439011');
   });
 
+  it('filters notifications by interactions category', async () => {
+    const notificationsRepository = {
+      findMine: jest.fn().mockResolvedValue([]),
+      countMine: jest.fn().mockResolvedValue(0),
+      countUnread: jest.fn().mockResolvedValue(0),
+    };
+    const notificationsGateway = {
+      emitUnreadCount: jest.fn(),
+    };
+
+    const service = new NotificationsService(
+      notificationsRepository as any,
+      notificationsGateway as any,
+    );
+
+    await service.getMine('507f1f77bcf86cd799439011', {
+      page: 1,
+      limit: 20,
+      category: 'interactions',
+    });
+
+    expect(notificationsRepository.findMine).toHaveBeenCalledWith(
+      '507f1f77bcf86cd799439011',
+      {
+        type: {
+          $in: [
+            'like',
+            'comment',
+            'reply',
+            'mention',
+            'save',
+            'share',
+            'collaboration_request',
+            'system',
+          ],
+        },
+      },
+      0,
+      20,
+      { createdAt: -1 },
+    );
+  });
+
+  it('keeps type filter priority over category for backward compatibility', async () => {
+    const notificationsRepository = {
+      findMine: jest.fn().mockResolvedValue([]),
+      countMine: jest.fn().mockResolvedValue(0),
+      countUnread: jest.fn().mockResolvedValue(0),
+    };
+    const notificationsGateway = {
+      emitUnreadCount: jest.fn(),
+    };
+
+    const service = new NotificationsService(
+      notificationsRepository as any,
+      notificationsGateway as any,
+    );
+
+    await service.getMine('507f1f77bcf86cd799439011', {
+      page: 1,
+      limit: 20,
+      type: 'message',
+      category: 'interactions',
+    });
+
+    expect(notificationsRepository.findMine).toHaveBeenCalledWith(
+      '507f1f77bcf86cd799439011',
+      { type: 'message' },
+      0,
+      20,
+      { createdAt: -1 },
+    );
+  });
+
   it('creates system notifications with system resource mapping when requested', async () => {
     const notificationsRepository = {
       create: jest.fn().mockResolvedValue({ toJSON: () => ({ _id: 'notification-1' }) }),