fix(stats): review fuzzy AniList duplicates before merging

- Preserve merged title aliases for future episodes
- Fail closed when queued writes cannot drain

stats/src/hooks/useAnimeLibrary.ts

@@ -1,11 +1,16 @@
 import { useCallback, useState, useEffect } from 'react';
 import { getStatsClient } from './useStatsApi';
-import type { AnimeLibraryItem } from '../types/stats';
+import type { AnimeLibraryItem, StatsAnimeMergeRecommendation } from '../types/stats';
+
+const BACKGROUND_REFRESH_MS = 30_000;
 
 export function useAnimeLibrary() {
   const [anime, setAnime] = useState<AnimeLibraryItem[]>([]);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
+  const [recommendations, setRecommendations] = useState<StatsAnimeMergeRecommendation[]>([]);
+  const [dismissingRecommendationId, setDismissingRecommendationId] = useState<number | null>(null);
+  const [recommendationActionError, setRecommendationActionError] = useState<string | null>(null);
   const [reloadToken, setReloadToken] = useState(0);
 
   const reload = useCallback(() => {
@@ -14,10 +19,14 @@ export function useAnimeLibrary() {
 
   useEffect(() => {
     let cancelled = false;
-    getStatsClient()
+    const client = getStatsClient();
+    client
       .getAnimeLibrary()
       .then((data) => {
-        if (!cancelled) setAnime(data);
+        if (!cancelled) {
+          setAnime(data);
+          setError(null);
+        }
       })
       .catch((err: Error) => {
         if (!cancelled) setError(err.message);
@@ -25,10 +34,68 @@ export function useAnimeLibrary() {
       .finally(() => {
         if (!cancelled) setLoading(false);
       });
+
+    // Recommendation support is deliberately non-blocking. An older backend
+    // should still be able to display its library even when this endpoint is
+    // unavailable.
+    client
+      .getAnimeMergeRecommendations()
+      .then((data) => {
+        if (!cancelled) {
+          setRecommendations(data.recommendations);
+          setRecommendationActionError(null);
+        }
+      })
+      .catch(() => {
+        // Preserve the last confirmed set. A transient polling failure should
+        // not make a pending review silently disappear.
+      });
     return () => {
       cancelled = true;
     };
   }, [reloadToken]);
 
-  return { anime, loading, error, reload };
+  useEffect(() => {
+    const refreshOnFocus = () => reload();
+    const interval = window.setInterval(reload, BACKGROUND_REFRESH_MS);
+    window.addEventListener('focus', refreshOnFocus);
+    return () => {
+      window.clearInterval(interval);
+      window.removeEventListener('focus', refreshOnFocus);
+    };
+  }, [reload]);
+
+  const dismissRecommendation = useCallback(async (recommendationId: number) => {
+    setDismissingRecommendationId(recommendationId);
+    setRecommendationActionError(null);
+    try {
+      await getStatsClient().dismissAnimeMergeRecommendation(recommendationId);
+      setRecommendations((current) =>
+        current.filter((item) => item.recommendationId !== recommendationId),
+      );
+    } catch {
+      setRecommendationActionError('Could not dismiss this suggestion. Try again.');
+    } finally {
+      setDismissingRecommendationId(null);
+    }
+  }, []);
+
+  const clearRecommendation = useCallback((recommendationId: number) => {
+    setRecommendations((current) =>
+      current.filter((item) => item.recommendationId !== recommendationId),
+    );
+    setRecommendationActionError(null);
+  }, []);
+
+  return {
+    anime,
+    loading,
+    error,
+    reload,
+    recommendations,
+    dismissRecommendation,
+    dismissingRecommendationId,
+    recommendationActionError,
+    clearRecommendation,
+  };
 }

stats/src/hooks/useModalFocus.ts

@@ -0,0 +1,73 @@
+import { useEffect, useRef, type RefObject } from 'react';
+
+const FOCUSABLE_SELECTOR = [
+  'button:not([disabled])',
+  'input:not([disabled])',
+  'select:not([disabled])',
+  'textarea:not([disabled])',
+  'a[href]',
+  '[tabindex]:not([tabindex="-1"])',
+].join(',');
+
+interface UseModalFocusOptions {
+  dialogRef: RefObject<HTMLElement | null>;
+  initialFocusRef: RefObject<HTMLElement | null>;
+  dismissDisabled?: boolean;
+  onDismiss: () => void;
+}
+
+export function useModalFocus({
+  dialogRef,
+  initialFocusRef,
+  dismissDisabled = false,
+  onDismiss,
+}: UseModalFocusOptions): void {
+  const dismissDisabledRef = useRef(dismissDisabled);
+  const onDismissRef = useRef(onDismiss);
+  dismissDisabledRef.current = dismissDisabled;
+  onDismissRef.current = onDismiss;
+
+  useEffect(() => {
+    const previouslyFocused =
+      document.activeElement instanceof HTMLElement ? document.activeElement : null;
+    initialFocusRef.current?.focus();
+
+    const handleKeyDown = (event: KeyboardEvent) => {
+      if (event.key === 'Escape') {
+        if (!dismissDisabledRef.current) {
+          event.preventDefault();
+          onDismissRef.current();
+        }
+        return;
+      }
+      if (event.key !== 'Tab') return;
+
+      const dialog = dialogRef.current;
+      if (!dialog) return;
+      const focusable = [...dialog.querySelectorAll<HTMLElement>(FOCUSABLE_SELECTOR)];
+      const first = focusable[0];
+      const last = focusable.at(-1);
+      if (!first || !last) return;
+
+      if (
+        event.shiftKey &&
+        (document.activeElement === first || !dialog.contains(document.activeElement))
+      ) {
+        event.preventDefault();
+        last.focus();
+      } else if (
+        !event.shiftKey &&
+        (document.activeElement === last || !dialog.contains(document.activeElement))
+      ) {
+        event.preventDefault();
+        first.focus();
+      }
+    };
+
+    document.addEventListener('keydown', handleKeyDown);
+    return () => {
+      document.removeEventListener('keydown', handleKeyDown);
+      previouslyFocused?.focus();
+    };
+  }, [dialogRef, initialFocusRef]);
+}