Mirrors the autotrader stack's auto-deploy: fetch every minute, act when master
moves, lock against overlap, rewrite .last-check every run so a silent failure
is visible. Only extension/ and deploy/ changes publish - repacking for a docs
edit would republish an identical CRX every minute.
The guard is the part that earns its place. Chrome ignores a CRX that is not
strictly newer, so shipping extension changes without bumping manifest.json is
a no-op that looks exactly like success until someone notices the fix never
arrived. That now fails loudly instead.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
