diff --git a/.m11b2d_a1c_patch.py b/.m11b2d_a1c_patch.py
new file mode 100644
index 0000000..03fe387
--- /dev/null
+++ b/.m11b2d_a1c_patch.py
@@ -0,0 +1,70 @@
+# -*- coding: utf-8 -*-
+"""M11b-2d-A1c 外观债清理补丁脚本（一次性工具，不入库）。
+
+只对 tests/test_m11b2_single_tx.py 做三处定点替换，每处必须**恰好命中 1 次**，
+否则整体不写盘并 FAIL 退出——保证「禁改其它任何行」。
+"""
+import io
+import sys
+
+PATH = "tests/test_m11b2_single_tx.py"
+
+EDITS = [
+    # (名称, 原文, 新文)
+    ("1) TestLatency::test_p99_under_200ms vacuous 断言 -> 对 samples 逐次断言",
+     '        samples = []\n'
+     '        for i in range(100):\n'
+     '            res = self.apply("ev-l-%d" % i, states=[su(state={"hp": i})])\n'
+     '            self.assertTrue(res["ok"])\n'
+     '            samples.append(res["latency_ms"])\n',
+
+     '        results = []\n'
+     '        for i in range(100):\n'
+     '            res = self.apply("ev-l-%d" % i, states=[su(state={"hp": i})])\n'
+     '            self.assertTrue(res["ok"])\n'
+     '            results.append(res)\n'
+     '        samples = [r["latency_ms"] for r in results]\n'),
+
+    ("1b) 删除永真空生成器断言，改为逐次断言全部 res 的 sla_breach",
+     '        self.assertFalse(any(r["sla_breach"] for r in []))   # 见下条逐次断言\n',
+
+     '        for r in results:\n'
+     '            self.assertFalse(r["sla_breach"],\n'
+     '                             "latency_ms=%r 触发 sla_breach" % r["latency_ms"])\n'),
+
+    ("2a) for_update 用例中的死表达式 -> 仅保留两条真实断言",
+     '        self.assertEqual("", sqlmod.for_update_clause(SQLITE))\n'
+     '        self.assertIn("pbl_entity_state",\n'
+     '                      " ".join(s for s, _p in self_dummy_log()) if False else "pbl_entity_state")\n',
+
+     '        self.assertEqual("", sqlmod.for_update_clause(SQLITE))\n'),
+
+    ("2b) 删除配套空函数 self_dummy_log()",
+     '\n\ndef self_dummy_log():\n    return []\n',
+     '\n'),
+
+    ("3) assert_atomic_rollback 尾逗号（无意义元组）",
+     '        self.assertEqual(["BEGIN", "ROLLBACK"], k[-tail:]),\n',
+     '        self.assertEqual(["BEGIN", "ROLLBACK"], k[-tail:])\n'),
+]
+
+with io.open(PATH, "r", encoding="utf-8") as f:
+    src = f.read()
+
+orig_len = len(src)
+for name, old, new in EDITS:
+    n = src.count(old)
+    if n != 1:
+        print("FAIL: 锚点命中 %d 次（应为 1）: %s" % (n, name))
+        sys.exit(1)
+    src = src.replace(old, new, 1)
+    print("OK  : %s" % name)
+
+assert "self_dummy_log" not in src, "FAIL: self_dummy_log 残留"
+assert "for r in []" not in src, "FAIL: 空生成器断言残留"
+assert "if False else" not in src, "FAIL: 死表达式残留"
+assert 'k[-tail:]),' not in src, "FAIL: 尾逗号残留"
+
+with io.open(PATH, "w", encoding="utf-8") as f:
+    f.write(src)
+print("DONE: %s  %d -> %d 字符" % (PATH, orig_len, len(src)))