fix(character-dictionary): cache AniList media resolution to skip repeat

- Add anilist-resolution-cache.json to persist seriesKey→mediaId mappings
- Skip AniList search when a cached resolution or matching snapshot exists
- Expose readCachedSnapshots and readCachedMediaResolution from cache module

changes/character-dictionary-resolution-cache.md

@@ -0,0 +1,4 @@
+type: fixed
+area: character-dictionary
+
+- Reused cached character-dictionary media matches so loading a title with an existing snapshot no longer sends another AniList search request.

docs-site/character-dictionary.md

@@ -35,7 +35,7 @@ Character dictionary sync is disabled by default. To turn it on:
 ```
 
 ::: tip
-The first sync for a media title takes a few seconds while character data and portraits are fetched from AniList. Subsequent launches reuse the cached snapshot.
+The first sync for a media title takes a few seconds while character data and portraits are fetched from AniList. Subsequent launches reuse the cached media match and snapshot without a fresh AniList lookup.
 :::
 
 ::: warning
@@ -139,7 +139,7 @@ When `characterDictionary.enabled` is `true`, SubMiner runs an auto-sync routine
 5. **importing** — Push the ZIP into Yomitan. Waits for Yomitan mutation readiness (7-second timeout per operation).
 6. **ready** — Dictionary is live. Character names will match on the next subtitle line.
 
-**State tracking** is persisted in `character-dictionaries/auto-sync-state.json`:
+**State tracking** is persisted in `character-dictionaries/auto-sync-state.json`. AniList media matches are cached separately in `character-dictionaries/anilist-resolution-cache.json` so snapshot hits do not need another AniList search.
 
 ```jsonc
 {

src/main/character-dictionary-runtime.test.ts

@@ -1459,7 +1459,7 @@ test('generateForCurrentMedia preserves duplicate surface forms across different
   }
 });
 
-test('getOrCreateCurrentSnapshot persists and reuses normalized snapshot data', async () => {
+test('getOrCreateCurrentSnapshot reuses cached media resolution without AniList requests', async () => {
   const userDataPath = makeTempDir();
   const originalFetch = globalThis.fetch;
   let searchQueryCount = 0;
@@ -1567,11 +1567,18 @@ test('getOrCreateCurrentSnapshot persists and reuses normalized snapshot data',
     });
 
     const first = await runtime.getOrCreateCurrentSnapshot();
+    assert.equal(searchQueryCount, 1);
+    assert.equal(characterQueryCount, 1);
+
+    fs.rmSync(path.join(userDataPath, 'character-dictionaries', 'anilist-resolution-cache.json'), {
+      force: true,
+    });
+
     const second = await runtime.getOrCreateCurrentSnapshot();
 
     assert.equal(first.fromCache, false);
     assert.equal(second.fromCache, true);
-    assert.equal(searchQueryCount, 2);
+    assert.equal(searchQueryCount, 1);
     assert.equal(characterQueryCount, 1);
     assert.equal(
       fs.existsSync(path.join(userDataPath, 'character-dictionaries', 'cache.json')),

src/main/character-dictionary-runtime.ts

@@ -15,7 +15,10 @@ import {
   getMergedZipPath,
   getSnapshotPath,
   normalizeMergedMediaIds,
+  readCachedMediaResolution,
+  readCachedSnapshots,
   readSnapshot,
+  writeCachedMediaResolution,
   writeSnapshot,
 } from './character-dictionary-runtime/cache';
 import {
@@ -41,6 +44,7 @@ import type {
   CharacterDictionaryManualSelectionResult,
   CharacterDictionaryManualSelectionSnapshot,
   CharacterDictionaryRuntimeDeps,
+  CharacterDictionarySnapshot,
   CharacterDictionarySnapshotImage,
   CharacterDictionarySnapshotProgress,
   CharacterDictionarySnapshotProgressCallbacks,
@@ -204,6 +208,26 @@ export function createCharacterDictionaryRuntimeService(deps: CharacterDictionar
     };
   };
 
+  const findCachedSnapshotForSeriesKey = (
+    seriesKey: string,
+  ): CharacterDictionarySnapshot | null => {
+    return (
+      readCachedSnapshots(outputDir).find((snapshot) => {
+        const snapshotSeriesKey = buildCharacterDictionarySeriesKey({
+          mediaPath: null,
+          mediaTitle: snapshot.mediaTitle,
+          guess: {
+            title: snapshot.mediaTitle,
+            season: null,
+            episode: null,
+            source: 'fallback',
+          },
+        });
+        return snapshotSeriesKey === seriesKey;
+      }) ?? null
+    );
+  };
+
   const resolveCurrentMedia = async (
     targetPath?: string,
     beforeRequest?: () => Promise<void>,
@@ -228,7 +252,43 @@ export function createCharacterDictionaryRuntimeService(deps: CharacterDictionar
         staleMediaIds: override.staleMediaIds,
       };
     }
+
+    const cachedResolution = readCachedMediaResolution(outputDir, seriesKey);
+    if (cachedResolution) {
+      const cachedSnapshot = readSnapshot(getSnapshotPath(outputDir, cachedResolution.mediaId));
+      if (cachedSnapshot) {
+        deps.logInfo?.(
+          `[dictionary] cached AniList match: ${cachedSnapshot.mediaTitle} -> AniList ${cachedSnapshot.mediaId}`,
+        );
+        return {
+          id: cachedSnapshot.mediaId,
+          title: cachedSnapshot.mediaTitle,
+        };
+      }
+    }
+
+    const cachedSnapshot = findCachedSnapshotForSeriesKey(seriesKey);
+    if (cachedSnapshot) {
+      writeCachedMediaResolution(outputDir, {
+        seriesKey,
+        mediaId: cachedSnapshot.mediaId,
+        mediaTitle: cachedSnapshot.mediaTitle,
+      });
+      deps.logInfo?.(
+        `[dictionary] cached snapshot match: ${cachedSnapshot.mediaTitle} -> AniList ${cachedSnapshot.mediaId}`,
+      );
+      return {
+        id: cachedSnapshot.mediaId,
+        title: cachedSnapshot.mediaTitle,
+      };
+    }
+
     const resolved = await resolveAniListMediaIdFromGuess(guessed, beforeRequest);
+    writeCachedMediaResolution(outputDir, {
+      seriesKey,
+      mediaId: resolved.id,
+      mediaTitle: resolved.title,
+    });
     deps.logInfo?.(`[dictionary] AniList match: ${resolved.title} -> AniList ${resolved.id}`);
     return resolved;
   };

src/main/character-dictionary-runtime/cache.ts

@@ -21,6 +21,102 @@ export function getMergedZipPath(outputDir: string): string {
   return path.join(outputDir, 'merged.zip');
 }
 
+type MediaResolutionCacheEntry = {
+  seriesKey: string;
+  mediaId: number;
+  mediaTitle: string;
+};
+
+type MediaResolutionCacheFile = {
+  entries?: MediaResolutionCacheEntry[];
+};
+
+function getMediaResolutionCachePath(outputDir: string): string {
+  return path.join(outputDir, 'anilist-resolution-cache.json');
+}
+
+function normalizeMediaResolutionEntry(value: unknown): MediaResolutionCacheEntry | null {
+  if (!value || typeof value !== 'object') return null;
+  const raw = value as Partial<MediaResolutionCacheEntry>;
+  const seriesKey = typeof raw.seriesKey === 'string' ? raw.seriesKey.trim() : '';
+  const mediaTitle = typeof raw.mediaTitle === 'string' ? raw.mediaTitle.trim() : '';
+  if (typeof raw.mediaId !== 'number' || !Number.isFinite(raw.mediaId)) return null;
+  const mediaId = Math.floor(raw.mediaId);
+  if (!seriesKey || mediaId <= 0 || !mediaTitle) return null;
+  return {
+    seriesKey,
+    mediaId,
+    mediaTitle,
+  };
+}
+
+function readMediaResolutionEntries(outputDir: string): MediaResolutionCacheEntry[] {
+  try {
+    const parsed = JSON.parse(
+      fs.readFileSync(getMediaResolutionCachePath(outputDir), 'utf8'),
+    ) as MediaResolutionCacheFile;
+    if (!Array.isArray(parsed.entries)) return [];
+    const byKey = new Map<string, MediaResolutionCacheEntry>();
+    for (const value of parsed.entries) {
+      const normalized = normalizeMediaResolutionEntry(value);
+      if (normalized) byKey.set(normalized.seriesKey, normalized);
+    }
+    return [...byKey.values()];
+  } catch {
+    return [];
+  }
+}
+
+function writeMediaResolutionEntries(
+  outputDir: string,
+  entries: MediaResolutionCacheEntry[],
+): void {
+  ensureDir(outputDir);
+  fs.writeFileSync(
+    getMediaResolutionCachePath(outputDir),
+    JSON.stringify({ entries }, null, 2),
+    'utf8',
+  );
+}
+
+export function readCachedMediaResolution(
+  outputDir: string,
+  seriesKey: string,
+): MediaResolutionCacheEntry | null {
+  const normalizedKey = seriesKey.trim();
+  if (!normalizedKey) return null;
+  return (
+    readMediaResolutionEntries(outputDir).find((entry) => entry.seriesKey === normalizedKey) ?? null
+  );
+}
+
+export function writeCachedMediaResolution(
+  outputDir: string,
+  entry: MediaResolutionCacheEntry,
+): void {
+  const normalized = normalizeMediaResolutionEntry(entry);
+  if (!normalized) return;
+  const remaining = readMediaResolutionEntries(outputDir).filter(
+    (existing) => existing.seriesKey !== normalized.seriesKey,
+  );
+  writeMediaResolutionEntries(outputDir, [...remaining, normalized]);
+}
+
+export function readCachedSnapshots(outputDir: string): CharacterDictionarySnapshot[] {
+  let entries: fs.Dirent[] = [];
+  try {
+    entries = fs.readdirSync(getSnapshotsDir(outputDir), { withFileTypes: true });
+  } catch {
+    return [];
+  }
+
+  return entries
+    .filter((entry) => entry.isFile() && /^anilist-\d+\.json$/.test(entry.name))
+    .sort((left, right) => left.name.localeCompare(right.name))
+    .map((entry) => readSnapshot(path.join(getSnapshotsDir(outputDir), entry.name)))
+    .filter((snapshot): snapshot is CharacterDictionarySnapshot => snapshot !== null);
+}
+
 export function readSnapshot(snapshotPath: string): CharacterDictionarySnapshot | null {
   try {
     const raw = fs.readFileSync(snapshotPath, 'utf8');