phase29ao(p54): ssot composer v0/v1 adopt entrypoint

docs/development/current/main/design/coreloop-composer-v0-v1-boundary-ssot.md

@@ -0,0 +1,24 @@
+# CoreLoopComposer v0/v1 boundary SSOT
+
+This document fixes the responsibility boundary between CoreLoopComposer v0 and v1.
+
+## Scope
+
+- v0 handles loops where `value_join_needed == false`.
+- v1 handles loops where `value_join_needed == true`.
+- The selection is made at the composer entrypoints (not in the router).
+
+## Gates (current minimal contract)
+
+- v0: `value_join_needed == false`, `skeleton_kind == Loop`, return-only exits, no cleanup.
+- v1: `value_join_needed == true`, `skeleton_kind == Loop`, return-only exits, no cleanup.
+
+## Behavior
+
+- If the gate fails, v0/v1 returns `Ok(None)` and the caller falls back to legacy paths.
+- In strict/dev shadow adopt, a `None` result is treated as fail-fast with a clear error.
+
+## Notes
+
+- Pattern6 (ScanWithInit) currently has no v1 composition yet; v1 must return `None`.
+- Pattern2/3/5/7 value-join paths are intended to live in v1.

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 (P53 done)
+- Next step: TBD (P54 done)
 
 ## 2. すでに固めた SSOT（再発防止の土台）
 
@@ -42,6 +42,7 @@ Related:
 - post-phi final form: `docs/development/current/main/design/post-phi-final-form-ssot.md`
 - 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`
 
 ## 3. 移行タスクの流れ（安全順）