Optimize Loader

Anti-patterns to catch

1. Re-fetching data the caller already has

If a loader fetches a record (e.g. getVideoWithClipsById) and then passes just the ID to a downstream function that re-fetches the same record internally — change the downstream function's signature to accept the already-fetched object.

// BAD — getNextVideoId internally calls getVideoWithClipsById again
const video = yield * db.getVideoWithClipsById(videoId);
const nextId = yield * db.getNextVideoId(videoId);

// GOOD — pass the already-fetched video
const video = yield * db.getVideoWithClipsById(videoId);
const nextId = yield * db.getNextVideoId(video);

When refactoring signatures, type the parameter as the minimal shape needed, not the full return type: