Reviewer/push runs execute in a worker process, but the GitHub token was
cached by the webhook handler in the API server process — a different
process — so the worker's in-process cache was always cold. resolve_github_token
then failed (User not authenticated / Unknown source: github_push) and only the
app-token fallback kept reviews working, noisily.
The reviewer always acts as the GitHub App (open-swe[bot]), so resolve the
installation token directly at run start, scoped to the repo. This also bypasses
org SAML enforcement that blocks user OAuth tokens. Drop the now-dead
cross-process cache writes in the webhook reviewer-dispatch handlers, and stop
leave_failure_comment raising on the github_push source.