chore: archive v2.2 User Experience Polish milestone

Phases 28-31 archived to milestones/v2.2-phases/
Requirements and roadmap snapshots archived to milestones/

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.planning/STATE.md

@@ -4,13 +4,13 @@ milestone: v2.2
 milestone_name: User Experience Polish
 status: executing
 stopped_at: Phase 31 context gathered
-last_updated: "2026-04-12T18:50:04.872Z"
-last_activity: 2026-04-12
+last_updated: "2026-04-13T13:55:33.612Z"
+last_activity: 2026-04-13
 progress:
   total_phases: 36
   completed_phases: 24
-  total_plans: 67
-  completed_plans: 65
+  total_plans: 68
+  completed_plans: 66
   percent: 97
 ---
 
@@ -28,7 +28,7 @@ See: .planning/PROJECT.md (updated 2026-04-09)
 Phase: 31
 Plan: Not started
 Status: Executing Phase 30
-Last activity: 2026-04-12
+Last activity: 2026-04-13
 
 Progress: [░░░░░░░░░░] 0%