fix(mir): PHI検証panic修正 - update_cfg()を検証前に呼び出し

A案実装: debug_verify_phi_inputs呼び出し前にCFG predecessorを更新

修正箇所（7箇所）:
- src/mir/builder/phi.rs:50, 73, 132, 143
- src/mir/builder/ops.rs:273, 328, 351

根本原因:
- Branch/Jump命令でsuccessorは即座に更新
- predecessorはupdate_cfg()で遅延再構築
- PHI検証が先に実行されてpredecessor未更新でpanic

解決策:
- 各debug_verify_phi_inputs呼び出し前に
  if let Some(func) = self.current_function.as_mut() {
      func.update_cfg();
  }
  を挿入してCFGを同期

影響: if/else文、論理演算子(&&/||)のPHI生成が正常動作

tools/dev_stagea.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# dev_stagea.sh — Stage‑A (minimal) Hako → JSON v0 → Gate‑C 実行ヘルパー
+# 使い方:
+#   tools/dev_stagea.sh 'box Main { static method main() { print(1+2); } }'
+#   tools/dev_stagea.sh -f path/to/code.hako
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+BIN="$ROOT/target/release/nyash"
+
+if [ ! -x "$BIN" ]; then
+  echo "[info] building nyash (release) ..." >&2
+  (cd "$ROOT" && cargo build --release -q)
+fi
+
+CODE=""
+if [ "${1:-}" = "-f" ] && [ -n "${2:-}" ]; then
+  CODE="$(cat "$2")"
+elif [ -n "${1:-}" ]; then
+  CODE="$1"
+else
+  echo "Usage: $0 '<hako code>' | -f <file.hako>" >&2
+  exit 2
+fi
+
+RAW="/tmp/stagea_raw_$$.txt"
+OUT="/tmp/stagea_v0_$$.json"
+trap 'rm -f "$RAW" "$OUT"' EXIT
+
+# Stage‑A: compiler.hako に --source を渡して JSON v0 を 1 行出力
+NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_SYNTAX_SUGAR_LEVEL=full \
+NYASH_ENABLE_ARRAY_LITERAL=1 \
+HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
+NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
+"$BIN" --backend vm "$ROOT/lang/src/compiler/entry/compiler.hako" -- --source "$CODE" >"$RAW" 2>&1
+awk '/"version":0/ && /"kind":"Program"/ {print; exit}' "$RAW" >"$OUT" || {
+  echo "[error] JSON v0 not found in output" >&2
+  sed -n '1,80p' "$RAW" >&2
+  exit 1
+}
+
+# Gate‑C 実行（MIR Interpreter）
+NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 NYASH_NYRT_SILENT_RESULT=1 \
+"$BIN" --json-file "$OUT"
+
+exit $?
+

tools/dev_stageb.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# dev_stageb.sh — Stage‑B (ParserBox→FlowEntry) Hako → JSON v0 → Gate‑C 実行ヘルパー
+# 使い方:
+#   tools/dev_stageb.sh 'box Main { static method main() { print(1+2); } }'
+#   tools/dev_stageb.sh -f path/to/code.hako
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+BIN="$ROOT/target/release/nyash"
+STAGEA="$ROOT/tools/dev_stagea.sh"
+
+if [ ! -x "$BIN" ]; then
+  echo "[info] building nyash (release) ..." >&2
+  (cd "$ROOT" && cargo build --release -q)
+fi
+
+CODE=""
+if [ "${1:-}" = "-f" ] && [ -n "${2:-}" ]; then
+  CODE="$(cat "$2")"
+elif [ -n "${1:-}" ]; then
+  CODE="$1"
+else
+  echo "Usage: $0 '<hako code>' | -f <file.hako>" >&2
+  exit 2
+fi
+
+RAW="/tmp/stageb_raw_$$.txt"
+OUT="/tmp/stageb_v0_$$.json"
+trap 'rm -f "$RAW" "$OUT"' EXIT
+
+# Stage‑B: compiler.hako に --stage-b --source を渡して JSON v0 を 1 行出力
+# 必要な開発ENV（using/file許可とStage3）を付与
+NYASH_PARSER_ALLOW_SEMICOLON=1 \
+NYASH_SYNTAX_SUGAR_LEVEL=full \
+NYASH_ENABLE_ARRAY_LITERAL=1 \
+HAKO_ALLOW_USING_FILE=1 NYASH_ALLOW_USING_FILE=1 \
+HAKO_PARSER_STAGE3=1 NYASH_PARSER_STAGE3=1 \
+NYASH_VARMAP_GUARD_STRICT=0 NYASH_BLOCK_SCHEDULE_VERIFY=0 NYASH_PHI_VERIFY=0 \
+NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 \
+"$BIN" --backend vm "$ROOT/lang/src/compiler/entry/compiler.hako" -- --stage-b --source "$CODE" >"$RAW" 2>&1 || true
+
+if ! awk '/"version":0/ && /"kind":"Program"/ {print > out; found=1; exit} END{exit (!found)}' out="$OUT" "$RAW"; then
+  echo "[warn] Stage‑B emit failed or empty; falling back to Stage‑A" >&2
+  exec "$STAGEA" -f <(printf '%s\n' "$CODE")
+fi
+
+# Gate‑C 実行（MIR Interpreter）
+NYASH_QUIET=1 HAKO_QUIET=1 NYASH_CLI_VERBOSE=0 NYASH_NYRT_SILENT_RESULT=1 \
+"$BIN" --json-file "$OUT"
+
+exit $?
+

tools/smokes/v2/README.md

@@ -81,6 +81,7 @@ tools/smokes/v2/
 
 - `SMOKES_ENABLE_CORE_CANARY=1` — Core interpreter canaries（emit→nyvm/core, Gate‑C Core）。
 - `SMOKES_ENABLE_STAGEB=1` — Selfhost Stage‑B canaries（`selfhost_stageb_{binop,if,index}_vm.sh`）。
+- `SMOKES_ENABLE_STAGEB_V1=1` — Stage‑B v1 互換カナリア（`selfhost_stageb_v1_compat_vm.sh`）。未配線時は SKIP。
 
 ## 🔧 テスト作成規約