* fix(anilist): paginate large libraries to avoid CPU budget kills
Chunk GraphQL fetches and defer merge, sort, and cover work to update()
ticks so 1000+ anime and manga entries load without blocking callbacks.
* fix(anilist): handle OAuth callback immediately and simplify service helpers
Process browser login tokens synchronously from runStream and file poll, keep a 500ms update interval during OAuth, and avoid duplicate OAuth result emissions from Python.
