docs(phase-20): complete phase execution — verification passed (9/9), advisory review

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.planning/STATE.md

@@ -2,13 +2,13 @@
 gsd_state_version: 1.0
 milestone: v1.1
 milestone_name: Operability & Polish
-current_phase: 20
-current_phase_name: admin-member-editor-form-declutter
+current_phase: 999.1
+current_phase_name: BACKLOG
 status: executing
 stopped_at: Phase 20 UI-SPEC approved
-last_updated: "2026-06-18T21:40:44.719Z"
+last_updated: "2026-06-18T21:47:42.443Z"
 last_activity: 2026-06-18
-last_activity_desc: Phase 20 execution started
+last_activity_desc: Phase 20 complete, transitioned to Phase 999.1
 progress:
   total_phases: 27
   completed_phases: 13
@@ -28,10 +28,10 @@ See: .planning/PROJECT.md (updated 2026-06-16)
 
 ## Current Position
 
-Phase: 20 (admin-member-editor-form-declutter) — EXECUTING
-Plan: 2 of 3
+Phase: 999.1 — Treat Fastmail as one calendar provider; framework supports adding more providers (BACKLOG)
+Plan: Not started
 Status: Ready to execute
-Last activity: 2026-06-18 — Phase 20 execution started
+Last activity: 2026-06-18 — Phase 20 complete, transitioned to Phase 999.1
 
 ### ✅ Resolved Checkpoint — Phase 15 Plan 15-03 Task 2 (human-action)
 
@@ -41,7 +41,7 @@ Done 2026-06-12. Gitea branch protection on `main` now requires EXACTLY `CI / fa
 
 **Velocity:**
 
-- Total plans completed: 66
+- Total plans completed: 69
 - Average duration: -
 - Total execution time: 0 hours
 
@@ -62,6 +62,7 @@ Done 2026-06-12. Gitea branch protection on `main` now requires EXACTLY `CI / fa
 | 12 | 7 | - | - |
 | 19 | 5 | - | - |
 | 17 | 6 | - | - |
+| 20 | 3 | - | - |
 
 **Recent Trend:**