feat(notifications): add ntfy as a first-class notification channel

Adds ntfy.sh (and self-hosted instances) as a new push notification
channel with full parity to the existing webhook channel.

- Backend: NtfyConfig type, getUserNtfyConfig, getAdminNtfyConfig,
  resolveNtfyUrl, sendNtfy (header-based API with Title/Priority/Tags/
  Click headers), testNtfy, NTFY_EVENT_META (priority + emoji tags per
  event), SSRF guard via existing checkSsrf + createPinnedDispatcher
- notificationPreferencesService: ntfy added to NotifChannel union,
  IMPLEMENTED_COMBOS, getActiveChannels parser, getAvailableChannels,
  ADMIN_GLOBAL_CHANNELS, and AvailableChannels interface
- notificationService: per-user ntfy dispatch after webhook block;
  admin-scoped ntfy via getAdminGlobalPref for version_available events
- Routes: POST /api/notifications/test-ntfy with saved-token fallback
- authService: admin_ntfy_server/topic/token in ADMIN_SETTINGS_KEYS,
  masked + encrypted on read/write
- settingsService: ntfy_token added to ENCRYPTED_SETTING_KEYS
- Frontend: ntfy topic/server/token inputs + Save/Test/Clear buttons in
  NotificationsTab; admin Ntfy panel in AdminPage; testNtfy API method
- i18n: full English strings; English placeholders in 14 other locales
- Tests: resolveNtfyUrl, sendNtfy, dispatch integration, UI tests,
  MSW handler for test-ntfy endpoint

server/tests/integration/notifications.test.ts

@@ -348,6 +348,43 @@ describe('Notification test endpoints', () => {
     expect(res.status).toBe(200);
     expect(res.body).toHaveProperty('success');
   });
+
+  it('NOTIF-007 — POST /api/notifications/test-ntfy returns 400 when no topic configured', async () => {
+    const { user } = createUser(testDb);
+
+    const res = await request(app)
+      .post('/api/notifications/test-ntfy')
+      .set('Cookie', authCookie(user.id))
+      .send({});
+
+    expect(res.status).toBe(400);
+    expect(res.body).toHaveProperty('error');
+  });
+
+  it('NOTIF-008 — POST /api/notifications/test-ntfy with explicit topic returns 200', async () => {
+    const { user } = createUser(testDb);
+
+    const res = await request(app)
+      .post('/api/notifications/test-ntfy')
+      .set('Cookie', authCookie(user.id))
+      .send({ topic: 'trek-integration-test-topic' });
+
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveProperty('success');
+  });
+
+  it('NOTIF-009 — POST /api/notifications/test-ntfy falls back to user saved topic', async () => {
+    const { user } = createUser(testDb);
+    testDb.prepare("INSERT OR REPLACE INTO settings (user_id, key, value) VALUES (?, 'ntfy_topic', 'saved-user-topic')").run(user.id);
+
+    const res = await request(app)
+      .post('/api/notifications/test-ntfy')
+      .set('Cookie', authCookie(user.id))
+      .send({});
+
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveProperty('success');
+  });
 });
 
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