phase29ab(p5): freeze pattern7 split-scan near-miss with fixture+smoke

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

@@ -1,6 +1,6 @@
 # Self Current Task — Now (main)
 
-## Current Focus: Phase 29ab P4（Phase 263 realworld seg: Derived slot）
+## Current Focus: Phase 29ab P5（Pattern7 SplitScan contract fail-fast）
 
 **2025-12-28: Phase 29ab P1 完了** ✅
 - 目的: Pattern2 の LoopBodyLocal promotion の最小ケースを fixture+integration smoke で固定
@@ -27,6 +27,13 @@
 - Smoke: `tools/smokes/v2/profiles/integration/apps/phase263_pattern2_seg_realworld_min_vm.sh`
 - 追加/調整: `String.indexOf(search, fromIndex)` の2引数対応（arity解決を含む）を VM/JoinIR lowering 側で整備
 
+**2025-12-28: Phase 29ab P5 完了** ✅
+- 目的: Pattern7 SplitScan の「形は近いが契約違反」ケースを extractor 段で freeze に固定（SSOT化）
+- 実装: `src/mir/builder/control_flow/joinir/patterns/pattern7_split_scan.rs`（`freeze_with_hint("phase29ab/pattern7/contract", ...)`）
+- fixture: `apps/tests/phase29ab_pattern7_firstfail_min.hako`
+- smoke: `tools/smokes/v2/profiles/integration/apps/phase29ab_pattern7_firstfail_min_vm.sh`
+- 検証: `./tools/smokes/v2/run.sh --profile integration --filter "phase29ab_pattern7_*"` PASS
+
 **2025-12-28: Phase 29aa P5 完了** ✅
 - 目的: Return block が複数 predecessor のとき、incoming state が完全一致する場合のみ ReturnCleanup を成立させる
 - 入口: `docs/development/current/main/phases/phase-29aa/README.md`