phase29ap(p13): remove dead code after legacy removal

docs/development/current/main/10-Now.md

@@ -3,7 +3,7 @@
 ## Current Focus
 
 - Phase: `docs/development/current/main/phases/phase-29ap/README.md`
-- Next: Phase 29ap P13 (planned; see `docs/development/current/main/phases/phase-29ap/README.md`)
+- Next: Phase 29ap P14 (planned; see `docs/development/current/main/phases/phase-29ap/README.md`)
 
 ## Gate (SSOT)
 

docs/development/current/main/30-Backlog.md

@@ -5,7 +5,7 @@ Scope: 「次にやる候補」を短く列挙するメモ。入口は `docs/dev
 
 ## Active
 
-- Phase 29ap: `docs/development/current/main/phases/phase-29ap/README.md` (Next: P13 planned)
+- Phase 29ap: `docs/development/current/main/phases/phase-29ap/README.md` (Next: P14 planned)
 - JoinIR regression gate SSOT: `docs/development/current/main/phases/phase-29ae/README.md`
 - CorePlan hardening (docs-first): `docs/development/current/main/phases/phase-29al/README.md`
 

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-29ap/README.md`
-- Next step: Phase 29ap P13 (planned)
+- Next step: Phase 29ap P14 (planned)
 
 ## 2. すでに固めた SSOT（再発防止の土台）
 

docs/development/current/main/phases/phase-29ap/README.md

@@ -137,6 +137,15 @@ Gate (SSOT):
   - No change to logs or error strings.
   - Gate stays green.
 
+## P13: Warning cleanup (dead_code) ✅
+
+- Scope:
+  - Remove unused JoinIR lowering modules (legacy remnants).
+  - Trim unused Pattern4 extractor fields.
+- Guardrails:
+  - No change to logs or error strings.
+  - Gate stays green.
+
 ## Next (planned)
 
-- P13: Dead-code cleanup (warnings-only, no behavior change)
+- P14: Phase 29ap closeout (docs-only)