fix(engine): 非中/西语轮注入 other 语言提醒——英文漂中文镜像修复（Task 11 对向）

历史护栏: 中文/西语会话纯拉丁轮不注入(护住 Task 11 场景);wall other 为
可选变体(存量快照/auto/生成器回退 DEFAULT_WALL,引擎部署即全租户生效)

Co-Authored-By: Claude Code <noreply@anthropic.com>

tests/test_lead_email_trigger.py

@@ -496,10 +496,32 @@ def test_reminder_language_note_follows_customer_language():
     assert "跟随客户语言自然表达" in es
     assert "号码逐字照抄" in es
     assert "英文原版" not in es and "绝不翻译" not in es   # 旧规则清零
-    # 英文客户不带语言提醒(默认英语,无需提醒)
+    # 2026-11-03 修正: 英文轮注入 other 语言提醒(默认英语方向此前无当轮
+    # 强制,system.md 压不住——中文语境+短英文查询整轮漂中文,与 Task 11
+    # 中文漂英文同款机理的镜像)
     en = ConversationManager._build_context_reminder(
         {}, "how much is the DN800 pipe?", [])
+    assert "语言提醒" in en and "不要出现汉字" in en
     assert "全程使用中文" not in en and "西语" not in en
+
+
+def test_language_note_other_history_guard():
+    """2026-11-03 历史护栏: 中文/西语会话中的纯拉丁轮(DN800/ok/型号)
+    维持无注入——历史语言自然延续;无条件注入 other 会把 Task 11 修好的
+    中文规格混排场景反向掰成英文。护栏只看客户消息(role=user)。"""
+    zh_hist = [{"role": "user", "content": "你们做DN800的HDPE双壁波纹管吗"},
+               {"role": "assistant", "content": "做的，您大概需要多少？"},
+               {"role": "user", "content": "300米"}]
+    r = ConversationManager._build_context_reminder({}, "DN800", zh_hist)
+    assert "语言提醒" not in r            # 中文会话纯拉丁轮: 不注入(现状保持)
+    es_hist = [{"role": "user", "content": "¿Cuál es el precio?"},
+               {"role": "assistant", "content": "Depende de la especificación"}]
+    r2 = ConversationManager._build_context_reminder({}, "DN110", es_hist)
+    assert "语言提醒" not in r2           # 西语会话纯拉丁轮: 同护栏
+    en_hist = [{"role": "user", "content": "how much for PE100?"},
+               {"role": "assistant", "content": "Need your specs first"}]
+    r3 = ConversationManager._build_context_reminder({}, "DN800", en_hist)
+    assert "语言提醒" in r3               # 纯英文会话: 照常注入
     # 有画像时同样生效(挂 parts 尾部)
     zh2 = ConversationManager._build_context_reminder(
         {"意向品类": "波纹管"}, "多少钱一米？", [])

tests/test_wall_schema.py

@@ -160,6 +160,46 @@ def test_template_with_literal_braces_rejected():
     assert "reminders.boundary.normal" in str(ei.value)
 
 
+# ---- 2026-11-03 英文漂中文修复: language_follow.other 可选变体 ----
+
+def test_language_follow_other_optional_variant():
+    """other 为可选变体: 在场则校验,缺省合法(auto 墙/生成器产出/生产 DB
+    快照无此键;运行期 _lang_note_for 回退 DEFAULT_WALL 文案)。设为必填
+    会让新代码编译旧生产快照即炸全部租户运行时——绝不改为必填。"""
+    import copy
+    base = _load("jiancai")
+    assert "other" in base["reminders"]["language_follow"]   # 出厂墙已有
+    compile_wall(base)                                       # 在场: 合法
+    without = copy.deepcopy(base)
+    del without["reminders"]["language_follow"]["other"]
+    compile_wall(without)                                    # 缺省: 合法
+    bad = copy.deepcopy(base)
+    bad["reminders"]["language_follow"]["other"] = ""
+    with pytest.raises(WallConfigError):
+        compile_wall(bad)                                    # 空串: 显性拒绝
+
+
+def test_language_follow_other_text_pinned():
+    """other 文案钉死关键语义: 纯反漂中文(不提任何语言分类——无重音符的
+    西/葡语客户会落进本桶,分类断言会把他们误导去英语)+模板句跟随+号码
+    照抄(与 zh/es 两条同款条款)。"""
+    note = _load("jiancai")["reminders"]["language_follow"]["other"]
+    assert "不要出现汉字" in note
+    assert "无法确定时用英语" in note
+    assert "跟随客户语言自然表达" in note and "逐字照抄" in note
+    assert "西语" not in note       # 措辞禁区: 不做语言分类断言
+
+
+def test_language_note_other_wall_fallback():
+    """租户墙无 other 键(auto/存量生产快照)→ _lang_note_for 回退
+    DEFAULT_WALL 文案——引擎部署即全租户生效,无需推配置。"""
+    from app.engine.services import conversation as conv
+    auto = compile_wall(_load("auto"))
+    assert "other" not in auto.reminders["language_follow"]   # 前提钉死
+    note = conv._lang_note_for("how much?", history=[], wall=auto)
+    assert "语言提醒" in note and "不要出现汉字" in note
+
+
 def test_template_with_unknown_placeholder_rejected():
     """I-2: 白名单外占位符({name})编译期拒绝——原属运行期 KeyError。"""
     cfg = _load("jiancai")