Phase 2: TypeOp変換の一本化（Optimizer安全ネット削除）\nPhase 3: 可視化/スナップショット基盤（--mir-verbose-effects, snapshot/compare/ci_check）\nDocs: Phase 1/2 完了マーク・利用方法追記

tools/compare_mir.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [ "$#" -ne 2 ]; then
+  echo "Usage: $0 <input.nyash> <golden.mir.txt>" >&2
+  exit 2
+fi
+
+INPUT="$1"
+GOLDEN="$2"
+
+TMPDIR="${TMPDIR:-/tmp}"
+OUT="$TMPDIR/mir_snapshot_$$.txt"
+trap 'rm -f "$OUT"' EXIT
+
+# Allow effect annotation opt-in via env var
+if [ -n "${NYASH_MIR_VERBOSE_EFFECTS:-}" ]; then
+  NYASH_MIR_VERBOSE_EFFECTS=1 ./tools/snapshot_mir.sh "$INPUT" "$OUT" >/dev/null
+else
+  ./tools/snapshot_mir.sh "$INPUT" "$OUT" >/dev/null
+fi
+
+if ! diff -u "$GOLDEN" "$OUT"; then
+  echo "MIR snapshot differs from golden: $GOLDEN" >&2
+  exit 1
+fi
+
+echo "MIR matches golden: $GOLDEN"
+