When dev-agent exhausts CI fix budget, writes escalation marker.
Supervisor picks it up next poll and invokes claude -p to diagnose
(flaky test? rate limit? real bug?) and decide: fix, close PR, or
escalate to human.
- Moved ci-debug.sh from dev/ to lib/ (shared utility)
- README: fixed supervisor description (all alerts go to claude)
- README: replaced implementation details with actual design principles