phase29ac(p1): normalize pattern6 reverse scan and flip smoke to PASS

docs/development/current/main/design/pattern6-7-contracts.md

@@ -24,7 +24,7 @@ Freeze conditions:
 - forward scan with step != `i = i + 1`
 - reverse scan with step != `i = i - 1`
 Note:
-- plan line is forward-only; reverse scans are currently treated as NotApplicable
+- plan line supports reverse scan (cond: `i >= 0`, step: `i = i - 1`)
 
 ## Pattern7 (SplitScan)
 

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

@@ -0,0 +1,24 @@
+# Phase 29ac: JoinIR thaw plan (Pattern6/7 near-miss → PASS)
+
+Goal: Convert freeze-fixed Pattern6/7 near-miss cases into PASS while keeping contracts intact (no by-name or silent fallback).
+
+## Target list (current freeze fixtures)
+
+- `apps/tests/phase29ab_pattern6_firstfail_min.hako`
+- `apps/tests/phase29ab_pattern6_matchscan_firstfail_min.hako`
+- `apps/tests/phase29ab_pattern7_firstfail_min.hako`
+
+## Pass order (recommended)
+
+1. **Pattern6 reverse scan**
+   - Plan/Normalizer: add reverse support (`i >= 0`, step `i = i - 1`).
+   - Smoke: `phase29ab_pattern6_reverse_firstfail_min` now OK PASS (RC=1).
+2. **Pattern6 matchscan missing step**
+   - Decide whether step can be synthesized safely; otherwise mark out-of-scope and add explicit contract note.
+3. **Pattern7 split-scan near-miss**
+   - Resolve then/else update mismatches without relaxing contracts.
+
+## Commands
+
+- `./tools/smokes/v2/run.sh --profile integration --filter "phase29ab_pattern6_*"`
+- `./tools/smokes/v2/run.sh --profile integration --filter "phase29ab_pattern7_*"`