feat: add pipeline-judge agent and evolution workflow system

- Add pipeline-judge agent for objective fitness scoring
- Update capability-index.yaml with pipeline-judge, evolution config
- Add fitness-evaluation.md workflow for auto-optimization
- Update evolution.md command with /evolve CLI
- Create .kilo/logs/fitness-history.jsonl for metrics logging
- Update AGENTS.md with new workflow state machine
- Add 6 new issues to MILESTONE_ISSUES.md for evolution integration
- Preserve ideas in agent-evolution/ideas/

Pipeline Judge computes fitness = (test_rate*0.5) + (gates*0.25) + (efficiency*0.25)
Auto-triggers prompt-optimizer when fitness < 0.70

.kilo/logs/fitness-history.jsonl

@@ -0,0 +1 @@
+{"ts":"2026-04-04T02:30:00Z","issue":5,"workflow":"feature","fitness":0.85,"breakdown":{"test_pass_rate":0.95,"quality_gates_rate":0.80,"efficiency_score":0.78},"tokens":38400,"time_ms":245000,"tests_passed":9,"tests_total":10,"agents":["requirement-refiner","history-miner","system-analyst","sdet-engineer","lead-developer"],"verdict":"PASS"}