docs(12): finalize plan — validation map, research resolution, roadmap waves

Resolve plan-checker warning (mark RESEARCH Open Questions RESOLVED),
fill VALIDATION.md Nyquist map (nyquist_compliant), record planning
complete in STATE, annotate ROADMAP wave dependencies.

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

.planning/ROADMAP.md

@@ -252,9 +252,17 @@ Plans:
 **Plans**: 4 plans in 3 waves
 
 Plans:
+**Wave 1**
+
 - [ ] 12-01-PLAN.md — Schema migration (nullable OIDC + claimed) + generate-secrets helper (SETUP-03) + Wave-0 scaffolds
+
+**Wave 2** *(blocked on Wave 1 completion)*
+
 - [ ] 12-02-PLAN.md — Pre-auth /api/setup/* router + isSetupLocked 423 guard + index mount + OIDC boot fallback (SETUP-01/02/04)
 - [ ] 12-03-PLAN.md — First-login-claims rework in upsertUser (D-08, SETUP-01)
+
+**Wave 3** *(blocked on Wave 2 completion)*
+
 - [ ] 12-04-PLAN.md — PWA SetupPage wizard + App.tsx gate + UI-SPEC revision (SETUP-01/02)
 
 **UI hint**: yes