diff --git a/docs/development/current/main/10-Now.md b/docs/development/current/main/10-Now.md
index b335fdd1..539666a8 100644
--- a/docs/development/current/main/10-Now.md
+++ b/docs/development/current/main/10-Now.md
@@ -2,6 +2,12 @@
 
 ## Current Focus: Phase 29ae (JoinIR Regression Pack)
 
+**2025-12-28: Phase 29ae P1 完了** ✅
+- 目的: Merge/Phi Contract SSOT + 回帰パック完全固定
+- 入口: `docs/development/current/main/phases/phase-29ae/README.md`
+- 追加: Header PHI Entry/Latch Contract の要点を SSOT 化
+- 検証: `./tools/smokes/v2/run.sh --profile integration --filter "phase1883_"` / `phase29ab_pattern2_` / `phase29ab_pattern6_` / `phase29ab_pattern7_` PASS
+
 **2025-12-28: Phase 29ae P0 完了** ✅
 - 目的: JoinIR の最小回帰セットを SSOT で固定
 - 入口: `docs/development/current/main/phases/phase-29ae/README.md`
diff --git a/docs/development/current/main/30-Backlog.md b/docs/development/current/main/30-Backlog.md
index a847638c..4152a60c 100644
--- a/docs/development/current/main/30-Backlog.md
+++ b/docs/development/current/main/30-Backlog.md
@@ -8,7 +8,7 @@ Related:
 
 ## 直近（JoinIR/selfhost）
 
-- **Phase 29ae（✅ COMPLETE）: JoinIR Regression Pack (docs-first)**
+- **Phase 29ae P1（✅ COMPLETE）: JoinIR Regression Pack (SSOT固定)**
   - 入口: `docs/development/current/main/phases/phase-29ae/README.md`
 
 - **Phase 29ad（✅ COMPLETE）: Naming SSOT for Pattern6/7 fixtures**
diff --git a/docs/development/current/main/phases/phase-29ae/README.md b/docs/development/current/main/phases/phase-29ae/README.md
index e42ac9e2..ac50edf2 100644
--- a/docs/development/current/main/phases/phase-29ae/README.md
+++ b/docs/development/current/main/phases/phase-29ae/README.md
@@ -9,13 +9,22 @@ Goal: JoinIR の最小回帰セットを SSOT として固定する。
 - Pattern7: `phase29ab_pattern7_*`
 - Merge/Phi代表: `apps/tests/phase1883_nested_minimal.hako`（RC=9）
 
+## Header PHI Entry/Latch Contract (SSOT)
+
+- Entry preds: `entry_incoming` のブロック + host entry block のみ
+- Latch preds: header の preds から entry preds を引いた残り
+- PHI inputs: entry preds は entry 値、latch preds は latch 値を流す
+- 根拠: `src/mir/builder/control_flow/joinir/merge/README.md`（Phase 29ae セクション）
+- 修正コミット: `11adec0ab`
+
 ## Commands
 
 - `./tools/smokes/v2/run.sh --profile integration --filter "phase29ab_pattern2_"`
 - `./tools/smokes/v2/run.sh --profile integration --filter "phase29ab_pattern6_"`
 - `./tools/smokes/v2/run.sh --profile integration --filter "phase29ab_pattern7_"`
-- `./tools/smokes/v2/run.sh --profile integration --filter "phase1883_"`
+- `./tools/smokes/v2/run.sh --profile integration --filter "phase1883_"`（RC=9 を PASS 扱い）
 
 ## Status
 
 - phase1883: PASS（RC=9 を成功扱い）
+- pattern2: PASS（JoinIR main param remap を carrier_order に揃える） `cf95afbd8`