Address QA warnings W-02 through W-07

W-02: Purge accepted connection requests after 90 days (rejected/cancelled stay at 30)
W-04: Rename shadowed `type` parameter to `notification_type` with alias
W-05: Extract notification type string literals to constants in connection service
W-06: Match notification list polling interval to unread count (15s when visible)
W-07: Add filter_to_shareable defence-in-depth gate on resolve_shared_profile output
W-03: Verified false positive — no double person lookup exists in accept flow

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

backend/app/jobs/notifications.py

@@ -277,17 +277,24 @@ async def _purge_old_notifications(db: AsyncSession) -> None:
 
 
 async def _purge_resolved_requests(db: AsyncSession) -> None:
-    """Remove rejected/cancelled connection requests older than 30 days.
+    """Remove resolved connection requests after retention period.
 
-    Note: resolved_at must be set when changing status to rejected/cancelled.
-    Rows with NULL resolved_at are preserved (comparison with NULL yields NULL).
-    Any future cancel endpoint must set resolved_at = now on status change.
+    Rejected/cancelled: 30 days. Accepted: 90 days (longer for audit trail).
+    resolved_at must be set when changing status. NULL resolved_at rows are
+    preserved (comparison with NULL yields NULL).
     """
-    cutoff = datetime.now() - timedelta(days=30)
+    reject_cutoff = datetime.now() - timedelta(days=30)
+    accept_cutoff = datetime.now() - timedelta(days=90)
     await db.execute(
         delete(ConnectionRequest).where(
             ConnectionRequest.status.in_(["rejected", "cancelled"]),
-            ConnectionRequest.resolved_at < cutoff,
+            ConnectionRequest.resolved_at < reject_cutoff,
+        )
+    )
+    await db.execute(
+        delete(ConnectionRequest).where(
+            ConnectionRequest.status == "accepted",
+            ConnectionRequest.resolved_at < accept_cutoff,
         )
     )
     await db.commit()

backend/app/routers/connections.py

@@ -40,6 +40,8 @@ from app.schemas.connection import (
 )
 from app.services.audit import get_client_ip, log_audit_event
 from app.services.connection import (
+    NOTIF_TYPE_CONNECTION_ACCEPTED,
+    NOTIF_TYPE_CONNECTION_REQUEST,
     SHAREABLE_FIELDS,
     create_person_from_connection,
     detach_umbral_contact,
@@ -229,11 +231,11 @@ async def send_connection_request(
     await create_notification(
         db,
         user_id=target.id,
-        type="connection_request",
+        type=NOTIF_TYPE_CONNECTION_REQUEST,
         title="New Connection Request",
         message=f"{sender_display} wants to connect with you",
         data={"sender_umbral_name": current_user.umbral_name},
-        source_type="connection_request",
+        source_type=NOTIF_TYPE_CONNECTION_REQUEST,
         source_id=conn_request.id,
     )
 
@@ -505,7 +507,7 @@ async def _respond_to_request_inner(
         await create_notification(
             db,
             user_id=sender_id,
-            type="connection_accepted",
+            type=NOTIF_TYPE_CONNECTION_ACCEPTED,
             title="Connection Accepted",
             message=f"{receiver_display} accepted your connection request",
             data={"connected_umbral_name": current_user.umbral_name},

backend/app/routers/notifications.py

@@ -23,7 +23,7 @@ router = APIRouter()
 @router.get("/", response_model=NotificationListResponse)
 async def list_notifications(
     unread_only: bool = Query(False),
-    type: str | None = Query(None, max_length=50),
+    notification_type: str | None = Query(None, max_length=50, alias="type"),
     page: int = Query(1, ge=1),
     per_page: int = Query(20, ge=1, le=100),
     db: AsyncSession = Depends(get_db),
@@ -34,8 +34,8 @@ async def list_notifications(
 
     if unread_only:
         base = base.where(Notification.is_read == False)  # noqa: E712
-    if type:
-        base = base.where(Notification.type == type)
+    if notification_type:
+        base = base.where(Notification.type == notification_type)
 
     # Total count
     count_q = select(func.count()).select_from(base.subquery())

backend/app/services/connection.py

@@ -18,6 +18,10 @@ from app.services.ntfy import send_ntfy_notification
 
 logger = logging.getLogger(__name__)
 
+# Notification type constants — keep in sync with notifications model CHECK constraint
+NOTIF_TYPE_CONNECTION_REQUEST = "connection_request"
+NOTIF_TYPE_CONNECTION_ACCEPTED = "connection_accepted"
+
 # Single source of truth — only these fields can be shared via connections
 SHAREABLE_FIELDS = frozenset({
     "first_name", "last_name", "preferred_name", "email", "phone", "mobile",
@@ -75,7 +79,12 @@ def resolve_shared_profile(
         elif field in _SETTINGS_FIELD_MAP and _SETTINGS_FIELD_MAP[field]:
             result[field] = getattr(settings, _SETTINGS_FIELD_MAP[field], None)
 
-    return result
+    return filter_to_shareable(result)
+
+
+def filter_to_shareable(profile: dict) -> dict:
+    """Strip any keys not in SHAREABLE_FIELDS. Defence-in-depth gate."""
+    return {k: v for k, v in profile.items() if k in SHAREABLE_FIELDS}
 
 
 def create_person_from_connection(

frontend/src/hooks/useNotifications.ts

@@ -64,7 +64,7 @@ export function NotificationProvider({ children }: { children: ReactNode }) {
       return data;
     },
     staleTime: 15_000,
-    refetchInterval: () => (visibleRef.current ? 60_000 : false),
+    refetchInterval: () => (visibleRef.current ? 15_000 : false),
   });
 
   const markReadMutation = useMutation({