Cost-optimized model routing for fix sessions

[michaeloboyle]

Description

Route fix sessions to the cheapest model that succeeds for each issue class. Track (issue_class, model, tokens, cost, success) and graduate simple classes to haiku.

Requirements

• Log model used, token count, cost, and success per fix
• For simple known classes (missing hover, alt text), try haiku first
• If haiku succeeds consistently (>90% over 5+ fixes), route permanently
• Fall back to sonnet/opus for complex/novel issues
• Ties into claude-flow 3-tier model routing (ADR-026)

Target

• 75% cost reduction for graduated issue classes
• No quality loss (fix correctness stays >90%)

Depends On

• Fix pattern library: store and reuse successful fix patterns #8 (Fix pattern library) — needs issue classification
• ADR-0006: DevTools Bridge integration #6 (DevTools Bridge integration) — Done

References

• PKM ADR-0013 Benchmarks: Self-Improvement Loop 5 (Cost Routing)
• PKM CLAUDE.md: 3-Tier Model Routing (ADR-026)