v0.5.8

Added

• Per-model toggle UI for stamp_model_rules: 6 toggle cards (Kimi K2.7,
  GLM 5.x, Coder, Kimi K3, Flash, Qwen) in the Experimental > Request Stamp
  section. Each toggle adds/removes a canonical PerModelRule entry — pure
  UI over the existing array, no backend logic change. Replaces the raw JSON
  editor (kind: 'json') with kind: 'modelRules'. Refs: ADR-0020,
  docs/reference/request-body-matrix.md.

Fixed

• Penalty badge tooltip: tooltip previously filtered budget categories
  through isOffending(), hiding healthy categories (interactive mode, low
  usage). Now renders all categories with humanized wording per Oracle review
  (section headers, urgency coloring, jargon removed: boxed→rate-limited,
  units_demoted→compute units demoted, broken run-on lines fixed).
• accountWide false-positive: interactive service mode no longer
  triggers the "Account-wide — all models" indicator, consistent with
  serviceModeTier which treats interactive as green.
• JSON validator blocked saves: the old kind: 'json' validator rejected
  arrays ("must be a JSON object"), blocking the Save button whenever
  stamp_model_rules had content. The new modelRules validator is a no-op;
  arrays pass. Backend had no such rule.