docs(phase29ao): add coreplan done criteria ssot

docs/development/current/main/design/coreplan-migration-done-criteria-ssot.md

@@ -0,0 +1,21 @@
+# CorePlan migration done criteria (SSOT)
+
+This document defines when the CorePlan migration can be considered done.
+
+## Stage-2 Done (release adopt)
+
+- Release adopt gate patterns execute via CorePlan without strict/dev flags.
+- Gate smokes cover the release paths and remain green.
+- The legacy path remains only as a fallback for non-gate cases.
+
+## Stage-3 Done (composer v0/v1)
+
+- Composition is driven by skeleton/feature facts, not pattern name branching.
+- Router is thin: it delegates to composer and does not encode v0/v1 decisions.
+- v0/v1 boundary is SSOT, keyed by `value_join_needed`, with clear gate rules.
+
+## Still allowed to remain
+
+- `DomainPlan` can remain as an intent layer for normalization/compatibility.
+- Legacy extractors and router branches remain until Phase 29ap removes them.
+

docs/development/current/main/design/coreplan-migration-roadmap-ssot.md

@@ -34,7 +34,7 @@ Related:
 ## 1.1 Current (active)
 
 - Active phase: `docs/development/current/main/phases/phase-29ao/README.md`
-- Next step: TBD (P54 done)
+- Next step: Phase 29ap (planned; P55 done)
 
 ## 2. すでに固めた SSOT（再発防止の土台）
 
@@ -43,6 +43,7 @@ Related:
 - effect classification: `docs/development/current/main/design/effect-classification-ssot.md`
 - cleanup contract: `docs/development/current/main/design/exitkind-cleanup-effect-contract-ssot.md`
 - composer v0/v1 boundary: `docs/development/current/main/design/coreloop-composer-v0-v1-boundary-ssot.md`
+- done criteria: `docs/development/current/main/design/coreplan-migration-done-criteria-ssot.md`
 
 ## 3. 移行タスクの流れ（安全順）