docs(phase-03): complete phase execution and verification

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.planning/STATE.md

@@ -2,13 +2,13 @@
 gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
-status: in-progress
+status: completed
 stopped_at: Completed 03-02-PLAN.md
-last_updated: "2026-03-11T18:16:10Z"
+last_updated: "2026-03-11T18:21:25.331Z"
 last_activity: 2026-03-11 -- Completed 03-02 (SSE push + command delivery)
 progress:
   total_phases: 4
-  completed_phases: 2
+  completed_phases: 3
   total_plans: 9
   completed_plans: 9
   percent: 95