fix(ai): extract reindex-button loading predicate + correct poll comment (PR #242)

F4: extract the reindex button `loading` predicate into a pure, unit-tested
`isReindexButtonLoading({ mutationPending, deadline, status })` next to the
other reindex helpers, replacing the inline JSX expression. Covers the
load-bearing post-cap case (deadline nulled, reindexing stale-true -> not
loading) plus mutationPending, active-run, and finished cases.

F5: rewrite the `useAiSettingsQuery` poll comment to match the actual
`nextReindexPollInterval` stop condition (continues while reindexing===true OR
within deadline and not fully indexed; stops only when reindexing===false &&
indexed>=total, or the deadline cap) instead of the stale "until indexed===total".

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/client/src/features/workspace/components/settings/components/ai-provider-settings.spec.tsx

@@ -5,6 +5,7 @@ import {
   resolveKeyField,
   nextReindexPollInterval,
   isReindexComplete,
+  isReindexButtonLoading,
 } from './ai-provider-settings';
 
 describe('resolveCardStatus', () => {
@@ -176,3 +177,49 @@ describe('isReindexComplete', () => {
     ).toBe(true);
   });
 });
+
+describe('isReindexButtonLoading', () => {
+  it('loads while the POST mutation is pending', () => {
+    expect(
+      isReindexButtonLoading({
+        mutationPending: true,
+        deadline: null,
+        status: false,
+      }),
+    ).toBe(true);
+  });
+
+  it('does NOT load post-cap: deadline nulled but reindexing left stale-true', () => {
+    // The key case: after the poll cap fires `reindexDeadline` is null while
+    // `settings.reindexing` can be a stale `true` from the last poll. Gating on
+    // the deadline keeps the spinner from sticking forever so the admin can
+    // restart.
+    expect(
+      isReindexButtonLoading({
+        mutationPending: false,
+        deadline: null,
+        status: true,
+      }),
+    ).toBe(false);
+  });
+
+  it('loads during an active run within the poll window', () => {
+    expect(
+      isReindexButtonLoading({
+        mutationPending: false,
+        deadline: 10_000,
+        status: true,
+      }),
+    ).toBe(true);
+  });
+
+  it('does not load once the run finished while still polling', () => {
+    expect(
+      isReindexButtonLoading({
+        mutationPending: false,
+        deadline: 10_000,
+        status: false,
+      }),
+    ).toBe(false);
+  });
+});

apps/client/src/features/workspace/components/settings/components/ai-provider-settings.tsx

@@ -215,6 +215,26 @@ export function isReindexComplete(status?: ReindexStatus): boolean {
   );
 }
 
+/**
+ * Whether the reindex button should show its spinner (and stay disabled).
+ *
+ * Spins while the POST is in flight, and for the WHOLE background run while the
+ * server reports `reindexing === true`. The `deadline !== null` gate is the
+ * load-bearing part: once the 120s poll cap fires it nulls `reindexDeadline`
+ * and stops refetching, so `status` (settings?.reindexing) can be a stale
+ * `true` from the last poll. Without the gate the spinner would stick forever
+ * for a run that outlives the cap and block a restart; gating on the active
+ * poll window clears it so the admin can re-trigger.
+ */
+export function isReindexButtonLoading(args: {
+  mutationPending: boolean;
+  deadline: number | null;
+  status?: boolean;
+}): boolean {
+  const { mutationPending, deadline, status } = args;
+  return mutationPending || (deadline !== null && status === true);
+}
+
 // Translate the dot's tooltip label. Kept in one place so all three endpoint
 // cards share identical wording.
 function cardStatusLabel(status: CardStatus, t: (k: string) => string): string {
@@ -1083,19 +1103,14 @@ export default function AiProviderSettings() {
               // Spin for the WHOLE run: the POST resolves immediately, but the
               // background job keeps running, so also stay loading while the
               // server reports `reindexing` (this also blocks a redundant
-              // re-trigger mid-run; the server de-dupes regardless).
-              //
-              // Gate the `reindexing` part on the active poll window
-              // (reindexDeadline !== null): once the 120s poll cap fires it nulls
-              // reindexDeadline and stops refetching, so `settings.reindexing`
-              // can be a stale `true` from the last poll. Without this gate the
-              // spinner would stay stuck (and the button disabled) forever for a
-              // run that outlives the cap — clearing it here lets the admin
-              // restart.
-              loading={
-                reindexMutation.isPending ||
-                (reindexDeadline !== null && settings?.reindexing === true)
-              }
+              // re-trigger mid-run; the server de-dupes regardless). The
+              // deadline gate (and why it matters post-cap) lives in
+              // `isReindexButtonLoading`, which is unit-tested.
+              loading={isReindexButtonLoading({
+                mutationPending: reindexMutation.isPending,
+                deadline: reindexDeadline,
+                status: settings?.reindexing,
+              })}
               onClick={() =>
                 reindexMutation.mutate(undefined, {
                   // Begin bounded polling so the counter climbs as the async

apps/client/src/features/workspace/queries/ai-settings-query.ts

@@ -23,8 +23,12 @@ export function useAiSettingsQuery(
   enabled: boolean = true,
   // While reindexing runs as an async background job, the counter only climbs
   // if the client keeps refetching. The component passes a refetchInterval
-  // function that polls until indexed === total or a bounded deadline, then
-  // returns false to stop. See AiProviderSettings.
+  // function (`nextReindexPollInterval`) that keeps polling while the server
+  // reports an active run (reindexing === true) OR we are still within the
+  // bounded deadline and not yet fully indexed; it returns false to stop only
+  // once the run has finished AND indexed >= total, or the deadline cap is hit
+  // (the cap always wins). Note: a transient indexed === total during an active
+  // run does NOT stop polling. See AiProviderSettings.
   refetchInterval?:
     | number
     | false