feat(cma): 口径裁定 2026-09-17 落地（现金流投资=0 二维判定 / 预警单位+期间口径）

依据：wecom-finance/reports/CMA_口径裁定_20260917.md（任总 2026-09-17 23:14「按建议执行」）

裁定1（现金流「投资活动净额=0」参与判定）
- classify_enterprise()：0 为合法输入；投资恒为 0 → 经营(±)×筹资(±) 二维映射出 2 个
  候选类型（candidate_type_nos/candidates），不再整体判「未判定」；投资栏 investing_note
  标注「本期无投资活动」；经营/筹资亦为 0 → 回退「未判定（无投资活动）」，不报错不静默
- /analysis 增 classification_dimension / investing_note / nets.investing.note；前端出
  二维横幅 + 候选行高亮 + 投资栏「本期无投资活动」（不给单一类型名）
- import_cashflow_statements.py：打印层修 2D（type_no=None）TypeError 崩溃；NA 措辞改为
  「按 0 参与判定」（机读短语 NA_PHRASE_TMPL/parse_na_activities 未动）

裁定2a（比率类单位统一「百分比(%)」口径，先做）
- 新增 app/utils/caliber_units.py：逐 KPI 对照表 RATIO_CALIBER_TABLE（唯一事实源）+ 判定侧
  唯一入口 resolve_caliber()；3 项需归一 ×100（流动/速动/毛利率），12 项取数已百分数不归一；
  表外且命中「疑似错配」窄形态（阈值子句量级≥100 且 0<|实测|<10 且单位属比率类）→
  dimension_suspect：不落预警、不推送（唯一规则，防 586/587 假红灯复发）
- alert_generator：判定前归一，文案写「口径归一 ×100（原值 1.29 → 129%）」留审计线索
- 新增 scripts/kpi_unit_crosscheck.py（只读对照表产出器）

裁定2b（期间由「当月硬编码」→「最近可用期间」，后做）
- resolve_latest_period()：取该 KPI 自己的最新 YYYY-MM（禁全局 MAX，防演示账套劫持）；
  伪期间（2026-H1/H2、2025-FY）在 Python 侧过滤（保「单测=生产」语义）
- 过渡期覆盖度自检扩展：记录回落后的期间分布 + 当月 0 条归因提示
- --dry-run（零写入零推送）作放行前抽查证据；generate_and_push/run_alert_check 支持 dry_run

测试：backend/tests/test_caliber_rulings_20260917.py 17 项；全量 1158 passed/1 xfailed

backend/app/api/cashflow_structure.py

@@ -94,9 +94,26 @@ CASHFLOW_TYPE_RULES = [
 # 类型 → 规则 快速索引
 TYPE_RULE_MAP = {r["type_no"]: r for r in CASHFLOW_TYPE_RULES}
 
+# ============================================================
+# 裁定1（2026-09-17 财务口径裁定）：投资活动净额 = 0 的合法输入与二维映射
+#   「投资活动净额=0」视为**本期无投资活动**，按 0 如实参与八类判定；
+#   三项中投资恒为 0 → 按 经营(±) × 筹资(±) **二维映射**到对应类型（候选 2 个，
+#   因投资符号未知）；投资栏位标注「本期无投资活动」。
+#   依据：wecom-finance/reports/CMA_口径裁定_20260917.md 裁定1
+# ============================================================
+INVESTING_ZERO_NOTE = "本期无投资活动"
+
+#: (经营符号, 筹资符号) → 投资符号未知时的候选类型号（对应类型由 8 类规则表反查）
+TWO_DIM_CANDIDATE_MAP = {
+    ("+", "-"): (1, 2),
+    ("+", "+"): (3, 4),
+    ("-", "-"): (5, 8),
+    ("-", "+"): (6, 7),
+}
+
 
 def _sign(value: Optional[float]) -> Optional[str]:
-    """净额符号：>0 → +，<0 → -，==0 → '0'（无法落入8类组合），None → None"""
+    """净额符号：>0 → +，<0 → -，==0 → '0'，None → None"""
     if value is None:
         return None
     if value > 0:
@@ -106,27 +123,86 @@ def _sign(value: Optional[float]) -> Optional[str]:
     return "0"
 
 
+def _rule_brief(type_no: int) -> dict:
+    """类型号 → 规则摘要（二维判定用的候选项，字段与三维判定保持一致）"""
+    r = TYPE_RULE_MAP[type_no]
+    return {
+        "type_no": r["type_no"], "name": r["name"], "health_emoji": r["health_emoji"],
+        "health_label": r["health_label"], "lifecycle": r["lifecycle"],
+        "o_sign": r["o_sign"], "i_sign": r["i_sign"], "f_sign": r["f_sign"],
+        "profile": r["profile"], "risk": r["risk"],
+    }
+
+
 def classify_enterprise(operating_net: Optional[float],
                         investing_net: Optional[float],
                         financing_net: Optional[float]) -> dict:
     """O/I/F 三净额符号 → 8类企业定性判定
 
     返回:
-      {classified, type_no, name, health_emoji, health_label, risk, profile, lifecycle, o_sign, i_sign, f_sign, reason}
-      classified=False 时 reason 说明未判定的原因（任一净额缺失或为0）
+      {classified, type_no, name, health_emoji, health_label, risk, profile, lifecycle,
+       dimension, o_sign, i_sign, f_sign, reason, investing_note?, candidate_type_nos?, candidates?}
+      classified=False 时 reason 说明未判定的原因。
+
+    2026-09-17 裁定1（财务口径）：
+      · **投资活动净额 = 0 是合法输入**（视为「本期无投资活动」），不再整体判「未判定」；
+      · 投资为 0 且经营/筹资可判 → **二维映射**（dimension="2D"，候选类型 2 个，
+        投资栏位 investing_note="本期无投资活动"）；
+      · 经营/筹资任一亦为 0 或缺失 → 回退「未判定（无投资活动）」，**不报错、不静默**。
     """
     o, i, f = _sign(operating_net), _sign(investing_net), _sign(financing_net)
-    if o is None or i is None or f is None:
-        missing = [name for sign, name in [(o, "经营"), (i, "投资"), (f, "筹资")] if sign is None]
-        return {"classified": False, "reason": "以下活动净额缺失：" + "、".join(missing) + "（需官方现金流量表数据）"}
-    if "0" in (o, i, f):
-        zero = [name for sign, name in [(o, "经营"), (i, "投资"), (f, "筹资")] if sign == "0"]
-        return {"classified": False, "reason": "以下活动净额为0（恰好为0无法落入8类正负组合）：" + "、".join(zero) + "，请按业务实质人工判定"}
+    names = {"o": "经营", "i": "投资", "f": "筹资"}
+
+    missing = [names[k] for k, s in (("o", o), ("i", i), ("f", f)) if s is None]
+    if missing:
+        return {"classified": False, "dimension": "0D",
+                "reason": "以下活动净额缺失：" + "、".join(missing) + "（需官方现金流量表数据）"}
+
+    zeros = [k for k, s in (("o", o), ("i", i), ("f", f)) if s == "0"]
+    inv_zero = i == "0"
+
+    if zeros:
+        # 恰好为 0 的维度：投资为 0 → 「本期无投资活动」；其余维度为 0 → 仍是有效输入但不可单独归类
+        zero_names = "、".join(names[k] for k in zeros)
+        if len(zeros) >= 2 or (o == "0" or f == "0"):
+            note = "（无投资活动）" if inv_zero else ""
+            return {
+                "classified": False, "dimension": "0D",
+                "o_sign": o, "i_sign": i, "f_sign": f,
+                "investing_note": INVESTING_ZERO_NOTE if inv_zero else None,
+                "reason": ("未判定%s：%s活动净额为 0（%s）且不足以二维归类，"
+                           "请按业务实质人工判定" % (
+                               note, zero_names,
+                               "投资活动为 0 = 本期无投资活动" if inv_zero else "该维度无正负号")),
+            }
+        # 单维为 0 且该维为投资 → 二维（经营 × 筹资）映射
+        pair = TWO_DIM_CANDIDATE_MAP.get((o, f)) if (o in ("+", "-") and f in ("+", "-")) else None
+        if pair:
+            cands = [_rule_brief(t) for t in pair]
+            return {
+                "classified": True,
+                "dimension": "2D",
+                "dimension_label": "二维判定（投资活动=0，本期无投资活动）",
+                "type_no": None,
+                "name": "/".join("%s %s" % (c["type_no"], c["name"]) for c in cands),
+                "candidate_type_nos": list(pair),
+                "candidates": cands,
+                "health_emoji": "", "health_label": None, "lifecycle": None,
+                "profile": "；".join("类型%d %s：%s" % (c["type_no"], c["name"], c["profile"]) for c in cands),
+                "risk": "；".join("类型%d：%s" % (c["type_no"], c["risk"]) for c in cands),
+                "o_sign": o, "i_sign": i, "f_sign": f,
+                "investing_note": INVESTING_ZERO_NOTE,
+                "reason": ("经营(%s) 投资(0=%s) 筹资(%s) → 二维映射候选：%s"
+                           "（投资活动为 0 无法定符号，需结合业务实质在候选中确认）" % (
+                               o, INVESTING_ZERO_NOTE, f,
+                               " / ".join("类型%d %s" % (c["type_no"], c["name"]) for c in cands))),
+            }
 
     for rule in CASHFLOW_TYPE_RULES:
         if rule["o_sign"] == o and rule["i_sign"] == i and rule["f_sign"] == f:
             return {
                 "classified": True,
+                "dimension": "3D",
                 "type_no": rule["type_no"],
                 "name": rule["name"],
                 "health_emoji": rule["health_emoji"],
@@ -135,9 +211,10 @@ def classify_enterprise(operating_net: Optional[float],
                 "profile": rule["profile"],
                 "risk": rule["risk"],
                 "o_sign": o, "i_sign": i, "f_sign": f,
+                "investing_note": None,
                 "reason": "经营(%s) 投资(%s) 筹资(%s) → 类型%d %s" % (o, i, f, rule["type_no"], rule["name"]),
             }
-    return {"classified": False, "reason": "未知组合，请检查数据"}
+    return {"classified": False, "dimension": "0D", "reason": "未知组合，请检查数据"}
 
 
 class CashFlowValueIn(BaseModel):
@@ -237,17 +314,21 @@ def get_analysis(
             "waterfall": None,
         }
 
+    classification = classify_enterprise(rec.operating_net, rec.investing_net, rec.financing_net)
+    i_sign = _sign(rec.investing_net)
+    # 裁定1：投资活动为 0 → 栏位显式标注「本期无投资活动」，避免读者误判为「收付相抵的 0」
+    investing_note = classification.get("investing_note") or (
+        INVESTING_ZERO_NOTE if i_sign == "0" else None)
+
     nets = {
         "operating": {"key": "operating", "name": "经营活动", "value": rec.operating_net,
-                      "sign": _sign(rec.operating_net), "unit": "万元"},
+                      "sign": _sign(rec.operating_net), "unit": "万元", "note": None},
         "investing": {"key": "investing", "name": "投资活动", "value": rec.investing_net,
-                      "sign": _sign(rec.investing_net), "unit": "万元"},
+                      "sign": i_sign, "unit": "万元", "note": investing_note},
         "financing": {"key": "financing", "name": "筹资活动", "value": rec.financing_net,
-                      "sign": _sign(rec.financing_net), "unit": "万元"},
+                      "sign": _sign(rec.financing_net), "unit": "万元", "note": None},
     }
 
-    classification = classify_enterprise(rec.operating_net, rec.investing_net, rec.financing_net)
-
     # 2. 瀑布图：期初现金 → +经营 → +投资 → +筹资 → 期末现金
     waterfall = None
     if rec.begin_cash is not None or rec.end_cash is not None:
@@ -279,6 +360,8 @@ def get_analysis(
         "remark": rec.remark,
         "nets": nets,
         "classification": classification,
+        "classification_dimension": classification.get("dimension"),
+        "investing_note": investing_note,
         "waterfall": waterfall,
     }