Indexing Check

Complete the GitHub Check Run for a finished reindex.

Distinct from /notify: that callback only fires for user-initiated runs (user_id is set). Auto-sync reindexes — the very ones that create a check — run with user_id=None, so Modal calls this endpoint unconditionally when a snapshot flips to ready / failed.

Looks up the snapshot's persisted github_check_run_id and PATCHes the run to success/failure. A no-op (no check created for this snapshot, no install covering the repo, checks disabled) returns ok silently. Strictly best-effort — a failure here must never break indexing.