worker-bugfix

Worker-owned least-cost bug-fixing procedure for one bounded behavior failure. Use when a symptom, regression, broken business flow, failing test, or production-path defect must be reproduced, localized, and fixed. Reuse prior failure shields, prefer rg for fresh source tracing, choose the cheapest discriminating red proof, make the smallest coherent fix, and preserve a reusable root-cause map entry when recurrence is likely.