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.test.ts

@@ -14,7 +14,8 @@ import {
   createRequest,
   listMyRequests,
   getRequest,
-  cancelRequest
+  cancelRequest,
+  hasInFlightRequest
 } from './requests';
 import { api, apiFetch } from './client';
 import { qk } from './queries';
@@ -155,3 +156,30 @@ describe('qk.myRequests', () => {
     expect(qk.myRequests()).toEqual(['myRequests']);
   });
 });
+
+describe('hasInFlightRequest', () => {
+  test('false for undefined / empty', () => {
+    expect(hasInFlightRequest(undefined)).toBe(false);
+    expect(hasInFlightRequest([])).toBe(false);
+  });
+
+  test('false when no row is approved', () => {
+    expect(
+      hasInFlightRequest([
+        { ...mockRow, status: 'pending' },
+        { ...mockRow, status: 'completed' },
+        { ...mockRow, status: 'rejected' }
+      ])
+    ).toBe(false);
+  });
+
+  test('true when at least one row is approved (mid-ingest)', () => {
+    expect(
+      hasInFlightRequest([
+        { ...mockRow, status: 'pending' },
+        { ...mockRow, status: 'approved' },
+        { ...mockRow, status: 'completed' }
+      ])
+    ).toBe(true);
+  });
+});