feat(azure-ai+gpu-ui): per-tenant Azure AI config + GPU health panel

- Per-tenant Azure AI config stored in tenants.tenant_config JSONB
- GET/PUT /api/tenants/{id}/ai-config + POST .../test connection
- api_key never returned to frontend (has_api_key: bool pattern)
- azure_ai.py resolves creds from tenant config when ai_enabled=True
- ai_tasks.py loads tenant config and passes it to validate_thumbnail
- Admin GPU Status section: probe button + status badge + last-checked time
- Notifications: _BELL_CHANNELS filter (notification+alert only in bell)
- Tenants.tsx: per-row Azure AI Config modal with URL auto-parse helper
- Remove duplicate in-memory /gpu-probe endpoints (kept DB-backed /probe/gpu)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/api/routers/notifications.py

@@ -51,30 +51,42 @@ def _visibility_filter(user: User):
     return and_(AuditLog.notification == True, targeted)  # noqa: E712
 
 
+# Default channels shown in bell dropdown
+_BELL_CHANNELS = ("notification", "alert")
+
+
 @router.get("", response_model=NotificationListResponse)
 async def list_notifications(
     limit: int = Query(20, ge=1, le=100),
     offset: int = Query(0, ge=0),
     unread_only: bool = Query(False),
+    channel: Optional[str] = Query(None, description="Filter by channel: notification, activity, alert. Defaults to notification+alert."),
     user: User = Depends(get_current_user),
     db: AsyncSession = Depends(get_db),
 ):
     vis = _visibility_filter(user)
 
+    # Channel filter
+    if channel:
+        channel_filter = AuditLog.channel == channel
+    else:
+        channel_filter = AuditLog.channel.in_(_BELL_CHANNELS)
+
     # Total count
-    total_q = select(func.count(AuditLog.id)).where(vis)
+    total_q = select(func.count(AuditLog.id)).where(vis, channel_filter)
     if unread_only:
         total_q = total_q.where(AuditLog.read_at.is_(None))
     total = (await db.execute(total_q)).scalar() or 0
 
-    # Unread count (always)
-    unread_q = select(func.count(AuditLog.id)).where(vis, AuditLog.read_at.is_(None))
+    # Unread count (always — only for bell channels, not activity)
+    bell_channel_filter = AuditLog.channel.in_(_BELL_CHANNELS)
+    unread_q = select(func.count(AuditLog.id)).where(vis, bell_channel_filter, AuditLog.read_at.is_(None))
     unread_count = (await db.execute(unread_q)).scalar() or 0
 
     # Items
     items_q = (
         select(AuditLog)
-        .where(vis)
+        .where(vis, channel_filter)
         .order_by(AuditLog.timestamp.desc())
         .offset(offset)
         .limit(limit)
@@ -105,7 +117,8 @@ async def unread_count(
     db: AsyncSession = Depends(get_db),
 ):
     vis = _visibility_filter(user)
-    q = select(func.count(AuditLog.id)).where(vis, AuditLog.read_at.is_(None))
+    bell_channel_filter = AuditLog.channel.in_(_BELL_CHANNELS)
+    q = select(func.count(AuditLog.id)).where(vis, bell_channel_filter, AuditLog.read_at.is_(None))
     count = (await db.execute(q)).scalar() or 0
     return UnreadCountResponse(unread_count=count)
 
@@ -182,7 +195,9 @@ async def update_my_notification_config(
 ):
     if channel not in ("in_app", "email"):
         raise HTTPException(status_code=400, detail="channel must be 'in_app' or 'email'")
-    return await upsert_notification_config(db, current_user.id, event_type, channel, body.enabled)
+    if body.frequency is not None and body.frequency not in ("immediate", "daily", "never"):
+        raise HTTPException(status_code=400, detail="frequency must be 'immediate', 'daily', or 'never'")
+    return await upsert_notification_config(db, current_user.id, event_type, channel, body.enabled, body.frequency)
 
 
 @router.post("/config/reset", response_model=list[NotificationConfigOut])