feat(track): add manga relations & recommendations query (AniList, MyAnimeList)

[VictorVow]

What this does

Adds a GraphQL mangaRelated query that returns relations and recommendations for a manga from AniList and MyAnimeList, so clients can show a "Related" view per manga.

mangaRelated(input: { mangaId: 42 }) {
  anilistRelations { remoteId title coverUrl trackingUrl relationType }
  anilistRecommendations { ... }
  myanimelistRelations { ... }
  myanimelistRecommendations { ... }
}

How the remote media id is resolved

For each tracker, per manga:

1. Existing track binding — if the manga is already tracked on that site, the bound remote id is used (authoritative, user-confirmed).
2. Title-search fallback — otherwise, if logged in, the manga title is searched on the tracker and the first result that is a confident title match is used. A loose/wrong top hit is never used.

A confident match is normalized equality, or Levenshtein similarity ≥ 0.9, compared against the candidate's primary and alternative titles (AniList romaji/english/native + synonyms, MAL en/ja + synonyms). This lets a localized source title match an entry whose primary title is in another language (e.g. an "Attack on Titan" source matching the romaji "Shingeki no Kyojin").

Per-tracker failures (not logged in, no match, network error) yield an empty list for that tracker instead of failing the whole query.

Implementation notes

• AniList relations/recommendations are fetched over the public (unauthenticated) GraphQL endpoint and filtered to type: MANGA (drops anime adaptations).
• MyAnimeList uses the related_manga and recommendations fields of the manga details endpoint.
• Alternative titles ride on the in-memory TrackSearch model only — not persisted to the DB and not exposed in the tracking GraphQL types.

Testing

• Builds, ktlintCheck clean.
• Verified the query end-to-end against a running server (empty path + live data).
• Verified the AniList and MyAnimeList request/response shapes against the live APIs.

Companion PR

The WebUI side (the "Related" button + modal) is Suwayomi/Suwayomi-WebUI#1122 and depends on this query being available.