Append entries as patterns emerge. Format: ## YYYY-MM-DD | Short description
After 3 occurrences of the same pattern (HIGH confidence), promote to a permanent rule update in the relevant rule file.
Rules:
- Log every failure pattern with: root cause, fix applied, confidence level (LOW/MEDIUM/HIGH)
- After 3 HIGH-confidence occurrences of the same pattern, update the canonical rule file
- Categories: use whatever fits your domain