Route explainability & operator trust (v1.21.x): lane family decision factors

[typelicious]

Summary

• Adds lane family decision factors table to dashboard Routes view
• Categorizes selection paths as same‑lane fallback, downgrade, primary
• Shows per‑family breakdown with colored pills (primary, same‑lane, downgrade, other)
• Extends routes KPIs with same‑lane fallback and downgrade traffic percentages
• Enhances route explainability for operator trust (v1.21.x roadmap)

Changes

• dashboard_web.py:
  • New HTML panel “Lane family decision factors” with 7‑column table
  • JavaScript helper functions categorizeSelectionPath, selectionPathCategoryLabel, selectionPathCategoryTone
  • Aggregation logic that groups selectionPaths by lane family, computes per‑category request counts, cost, latency, cooldown, recovered
  • Updates to routes KPIs showing same‑lane vs downgrade traffic percentages
  • Visual pills in selection‑paths bar list to indicate category

Notes

• Builds on route‑explainability foundation (v1.20.0)
• Selection‑path categorization follows router’s internal classification (same‑lane‑route, same‑cluster‑degrade, same‑benchmark‑degrade → same‑lane fallback; preferred‑degrade, fallback‑chain → downgrade; primary‑selected → primary)
• Real‑time cooldown timers and premium‑drift indicators remain for future iteration (v1.21.x)