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/requests.ts

@@ -3,6 +3,18 @@ import { api, apiFetch } from './client';
 import { qk } from './queries';
 import type { LidarrRequest, LidarrRequestKind } from './types';
 
+/** Cadence for in-flight request polling. Tuned to match the operator's
+    "fast enough to feel live, slow enough to not hammer the server"
+    threshold from #369. */
+const POLL_INTERVAL_MS = 12_000;
+
+/** True if any row is mid-ingest (status === 'approved'). The status flips
+    to 'completed' / 'rejected' when Lidarr finishes, so this predicate
+    lets the page poll exactly while there's something interesting to watch. */
+export function hasInFlightRequest(rows: readonly LidarrRequest[] | undefined): boolean {
+  return rows?.some((r) => r.status === 'approved') ?? false;
+}
+
 // CreateRequestParams is the shape callers pass; unused MBID fields are
 // optional, and we omit them from the wire body rather than sending empty
 // strings (the backend tolerates either, but this keeps test expectations
@@ -63,6 +75,14 @@ export function createMyRequestsQuery() {
   return createQuery({
     queryKey: qk.myRequests(),
     queryFn: listMyRequests,
-    staleTime: 60_000
+    staleTime: 60_000,
+    // Auto-poll while at least one user request is mid-ingest. Stops
+    // automatically when all rows are pending/completed/rejected.
+    // refetchIntervalInBackground defaults to false → polling pauses
+    // while the tab is hidden and resumes on focus.
+    refetchInterval: (query) =>
+      hasInFlightRequest(query.state.data as LidarrRequest[] | undefined)
+        ? POLL_INTERVAL_MS
+        : false
   });
 }