feat(web): auto-poll request progress when ingests are in flight (#369)

Half of #369 — the auto-poll piece. Inbox deferred (separate task).

Both /requests (user) and /admin/requests (admin, 'approved' tab only)
now refetch every 12s while at least one row has status='approved'.
Stops automatically when all rows settle to pending/completed/rejected.
TanStack Query's default refetchIntervalInBackground=false handles
the visibility behavior — polling pauses when the tab is hidden and
resumes on focus.

Predicate hasInFlightRequest() is exported + tested so the polling
logic is auditable independent of TanStack Query's internals.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/src/lib/api/admin.ts

@@ -116,10 +116,22 @@ export function createRootFoldersQuery(enabled: boolean = true) {
 export function createAdminRequestsQuery(status?: LidarrRequestStatus) {
   return createQuery({
     queryKey: qk.adminRequests(status),
-    queryFn: () => listAdminRequests(status)
+    queryFn: () => listAdminRequests(status),
+    // Only the 'approved' tab needs polling — that's where in-flight
+    // ingests live. Other tabs (pending/rejected/completed) are static
+    // until the operator acts on them.
+    refetchInterval: (query) => {
+      if (status !== 'approved') return false;
+      const rows = query.state.data as LidarrRequest[] | undefined;
+      return hasInFlightRequest(rows) ? 12_000 : false;
+    }
   });
 }
 
+function hasInFlightRequest(rows: readonly LidarrRequest[] | undefined): boolean {
+  return rows?.some((r) => r.status === 'approved') ?? false;
+}
+
 // Admin quarantine --------------------------------------------------------
 
 export async function listAdminQuarantine(): Promise<AdminQuarantineRow[]> {