feat(warning-p0a): 资金缺口阈值外置 + 复算对拍 + 讲人话(数字守恒) + 数据就绪核验

P0-A（任务 fullstack-20261017-warning-capability-build-p0）：
- cash_thresholds.py：阈值迁 per-entity（复用 alert_rules.rule_type=cash_gap_threshold，
  默认 20/10 万不动；无配置/非法/异常一律回落默认，fail-safe 不改预警行为）
- cash_forecast_engine.py：阈值改从配置读取，响应新增 threshold_source 明写来源
- verify_cash_gap_replay.py：同输入双跑逐字段 diff=0 + 手算 3/3 + 端点逐字段对拍(--live)
- cash_gap_narrative.py：复用 ai_brief.call_deepseek，只写原因/建议；
  断言生成文本数字集合 ⊆ 规则层数字集合，违例即不带文案上线
- audit_warning_data_readiness.py：G0 只读核验（cma_reader SELECT only），
  行数/期间/枚举 + 数据质量缺口（期初全 0、负期末、单批次、无员工维度表）

未 push（push 即部署，须项目侧书面放行）；未改生产库/未动 cron。

backend/app/api/alert_rules.py

@@ -21,6 +21,11 @@ from app.utils.alert_entity_scope import guard_alert_period, is_excluded_entity
 # 「实测区 / 预估区」分区口径（财务裁定 2026-10-02）：**预估行禁作预警依据**——
 # 本文件的取数读路径一律加 actual_only_clause()，动态阈值白名单去掉 estimated。
 from app.utils.kpi_value_scope import actual_only_clause
+# G1（2026-10-17）：资金缺口阈值的单一事实源（默认 20/10 万 + 参数校验）
+from app.utils.cash_thresholds import (
+    CASH_GAP_RULE_TYPE,
+    validate_params as validate_cash_gap_params,
+)
 
 logger = logging.getLogger("alert_rules")
 
@@ -32,6 +37,7 @@ VALID_RULE_TYPES = (
     "trend_down",       # 环比下降
     "forecast_deviation",   # 预测偏差（升级2b 2026-08-25）
     "customer_concentration",  # 客户集中度（P2 2026-09-10）
+    "cash_gap_threshold",   # 资金缺口阈值配置（G1 2026-10-17，配置行，不进预警生成链）
 )
 
 # ============================================================
@@ -130,6 +136,12 @@ def create_alert_rule(data: dict, db: Session = Depends(get_db), user=Depends(re
         raise HTTPException(404, "KPI不存在")
     if rule_type not in VALID_RULE_TYPES:  # 升级2b: 预测偏差 / P2-20260910: 客户集中度
         raise HTTPException(400, f"不支持的规则类型: {rule_type}")
+    # G1（2026-10-17）：资金缺口阈值为引擎级参数，入库前校验数值（非法配置一律拒收，
+    # 防「配置写坏 → 预警静默回落默认值」的假生效）。
+    if rule_type == CASH_GAP_RULE_TYPE:
+        err = validate_cash_gap_params(data.get("params"))
+        if err:
+            raise HTTPException(400, err)
 
     rule = AlertRule(
         entity_id=entity_id,
@@ -162,6 +174,12 @@ def update_alert_rule(rule_id: int, data: dict, db: Session = Depends(get_db), e
     for field in ("rule_type", "trigger_on", "enabled", "params"):
         if field in data:
             setattr(rule, field, data[field])
+    # G1（2026-10-17）：改完仍是资金阈值配置行 → 参数必须合法（拒收非法值）
+    if rule.rule_type == CASH_GAP_RULE_TYPE:
+        err = validate_cash_gap_params(rule.params)
+        if err:
+            db.rollback()
+            raise HTTPException(400, err)
     db.commit()
     db.refresh(rule)
     return {"data": {c.name: getattr(rule, c.name) for c in AlertRule.__table__.columns}}
@@ -189,6 +207,8 @@ def batch_create_rules(data: dict, db: Session = Depends(get_db), entity_id: int
         rule_type = rule_data.get("rule_type", "static")
         if rule_type not in VALID_RULE_TYPES:
             continue
+        if rule_type == CASH_GAP_RULE_TYPE and validate_cash_gap_params(rule_data.get("params")):
+            continue
         kpi = db.query(KPIDefinition).filter(KPIDefinition.id == kpi_id).first()
         if not kpi or kpi.entity_id != entity_id:
             continue
@@ -283,6 +303,10 @@ def run_all_alert_checks(db: Session = Depends(get_db), entity_id: int = Depends
     
     for rule in rules:
         try:
+            # G1（2026-10-17）：cash_gap_threshold 是资金引擎的参数配置行，不是 KPI 预警规则，
+            # 不进 KPIValue 比价链（否则未来若绑定到有值的 KPI 会误生成预警）。
+            if rule.rule_type == CASH_GAP_RULE_TYPE:
+                continue
             kpi = kpi_cache.get(rule.kpi_id)
             if kpi is None:
                 kpi = db.query(KPIDefinition).filter(KPIDefinition.id == rule.kpi_id).first()

backend/app/utils/cash_forecast_engine.py

@@ -13,9 +13,17 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger("cma.cash_forecast")
 
-# 默认现金阈值（万元）
-DEFAULT_CASH_WARNING = 20.0   # 黄灯 — 低于20万
-DEFAULT_CASH_CRITICAL = 10.0  # 红灯 — 低于10万
+# 默认现金阈值（万元）—— 单一事实源迁至 app/utils/cash_thresholds.py（G1，2026-10-17）
+# 此处保留同名常量以兼容既有 import（app/api/cash.py 等）；数值未变：黄 20 / 红 10。
+from app.utils.cash_thresholds import (  # noqa: E402
+    DEFAULT_CRITICAL as _CFG_DEFAULT_CRITICAL,
+    DEFAULT_WARNING as _CFG_DEFAULT_WARNING,
+    get_cash_gap_thresholds,
+    describe_source as describe_cash_threshold_source,
+)
+
+DEFAULT_CASH_WARNING = _CFG_DEFAULT_WARNING   # 黄灯 — 低于20万
+DEFAULT_CASH_CRITICAL = _CFG_DEFAULT_CRITICAL  # 红灯 — 低于10万
 
 # 历史KPI编码映射（含候选编码，兼容F_*标准编码）
 KPI_CODES = {
@@ -306,17 +314,27 @@ def forecast_cash_flow(
     db: Session,
     days: int = 30,
     current_cash: Optional[float] = None,
+    warning_line: Optional[float] = None,
+    critical_line: Optional[float] = None,
 ) -> dict:
     """
     预测未来30天现金流
-    
+
     算法：
     1. 获取历史经营现金流、应收、应付趋势
     2. 推算每日现金流入/流出
     3. 生成每日预测值+置信区间
+
+    阈值（G1，2026-10-17）：warning_line / critical_line 传 None 时取本账套配置
+    （alert_rules: cash_gap_threshold），未配置则默认 20/10 万；显式传入优先（便于复算对拍）。
     """
     from app.models import KPIDefinition, KPIValue
 
+    if warning_line is None or critical_line is None:
+        cfg_warning, cfg_critical = get_cash_gap_thresholds(db, entity_id)
+        warning_line = cfg_warning if warning_line is None else warning_line
+        critical_line = cfg_critical if critical_line is None else critical_line
+
     # 获取当前现金余额
     if current_cash is None:
         base_cash = get_current_cash_balance(db, entity_id)
@@ -375,9 +393,9 @@ def forecast_cash_flow(
         upper = cash + std * 0.5
 
         # 预警状态
-        if cash < DEFAULT_CASH_CRITICAL:
+        if cash < critical_line:
             status = "red"
-        elif cash < DEFAULT_CASH_WARNING:
+        elif cash < warning_line:
             status = "yellow"
         else:
             status = "green"
@@ -396,20 +414,20 @@ def forecast_cash_flow(
     min_date = next(f["date"] for f in forecast if f["predicted_cash"] == min_cash)
 
     suggestions = []
-    if min_cash < DEFAULT_CASH_CRITICAL:
+    if min_cash < critical_line:
         suggestions.append({
             "type": "critical",
-            "message": f"预计{min_date}现金余额降至{min_cash:.1f}万，低于警戒线{DEFAULT_CASH_CRITICAL}万",
+            "message": f"预计{min_date}现金余额降至{min_cash:.1f}万，低于警戒线{critical_line}万",
             "actions": [
                 "立即催收大额应收账款",
                 "暂停非必要支出",
                 "准备短期融资安排",
             ]
         })
-    elif min_cash < DEFAULT_CASH_WARNING:
+    elif min_cash < warning_line:
         suggestions.append({
             "type": "warning",
-            "message": f"预计{min_date}现金余额降至{min_cash:.1f}万，低于关注线{DEFAULT_CASH_WARNING}万",
+            "message": f"预计{min_date}现金余额降至{min_cash:.1f}万，低于关注线{warning_line}万",
             "actions": [
                 "加快应收账款回款",
                 "控制采购付款节奏",
@@ -606,8 +624,8 @@ def forecast_cash_flow_with_plans(
     db: Session,
     days: int = 30,
     current_cash: Optional[float] = None,
-    warning_line: float = DEFAULT_CASH_WARNING,
-    critical_line: float = DEFAULT_CASH_CRITICAL,
+    warning_line: Optional[float] = None,
+    critical_line: Optional[float] = None,
     include_plans: bool = True,
 ) -> dict:
     """
@@ -616,11 +634,21 @@ def forecast_cash_flow_with_plans(
     2. 叠加 cash_plans 的应收(收) / 应付(付)
     3. 识别资金缺口日期（余额 < 警戒线）
     4. 生成缺口前3天预警点
+
+    阈值来源（G1，2026-10-17）：None → 本账套配置（alert_rules: cash_gap_threshold）
+    → 未配置时默认 20/10 万；显式传入值优先（复算对拍用）。响应内 `threshold_source`
+    明写本次取值来源，便于页面标注与回执取证。
     """
     from collections import defaultdict
     from app.models import CashPlan
 
-    base = forecast_cash_flow(entity_id, db, days, current_cash)
+    if warning_line is None or critical_line is None:
+        cfg_warning, cfg_critical = get_cash_gap_thresholds(db, entity_id)
+        warning_line = cfg_warning if warning_line is None else warning_line
+        critical_line = cfg_critical if critical_line is None else critical_line
+
+    base = forecast_cash_flow(entity_id, db, days, current_cash,
+                              warning_line=warning_line, critical_line=critical_line)
     base_cash = base["base_cash"]
 
     # 预算校准：本月经营现金流预算优先作为基线（万元/月）
@@ -805,6 +833,7 @@ def forecast_cash_flow_with_plans(
         "days": days,
         "warning_line": warning_line,
         "critical_line": critical_line,
+        "threshold_source": describe_cash_threshold_source(db, entity_id),
         "budget_monthly_ocf": budget_ocf,
         "forecast": forecast,
         "gap_dates": gap_dates,

backend/app/utils/cash_thresholds.py

@@ -0,0 +1,133 @@
+# -*- coding: utf-8 -*-
+"""资金缺口阈值 —— per-entity 配置（复用 alert_rules 表，不新建表）
+
+任务：fullstack-20261017-warning-capability-build-p0 / G1（P0-A）
+方案依据：`_reports/yanxue-20261017-warning-capability-build-p0.md` §G1 + 决策点 D4（建议 B）
+
+口径（默认值不动）：
+  · 黄灯（warning） = 20.0 万元   —— 与改前 `cash_forecast_engine.DEFAULT_CASH_WARNING` 一致
+  · 红灯（critical）= 10.0 万元   —— 与改前 `cash_forecast_engine.DEFAULT_CASH_CRITICAL` 一致
+  · 配置存在时按配置；未配置 / 配置非法 / 读取异常 → **一律回落默认值**（fail-safe，不让预警失效）
+
+存储形态（零 DDL，复用现有 `alert_rules`）：
+  entity_id = 账套
+  rule_type = "cash_gap_threshold"
+  kpi_id    = 该账套现金余额 KPI（CASH_001 / BH_CASH_BALANCE 等），满足表 NOT NULL 约束
+  enabled   = 1
+  params    = {"warning": 20.0, "critical": 10.0}   # 单位：万元
+
+为什么单独一个 rule_type 而不复用 static：
+  static 规则走 `_check_static` 与 KPIValue 比价，参数语义是 `>=90` 之类表达式；
+  资金阈值是**引擎级参数**（决定缺口日判定与红黄分级），不是单条 KPI 的阈值。
+  独立 rule_type 让 `run_all_alert_checks` 的 if/elif 链自然跳过它（alert_level 保持 None），
+  不会生成预警行，也不影响现有 static/trend 规则。
+"""
+from __future__ import annotations
+
+import logging
+from typing import Any, Dict, Optional, Tuple
+
+logger = logging.getLogger("cma.cash_thresholds")
+
+#: alert_rules.rule_type 取值（配置行，不进预警生成链）
+CASH_GAP_RULE_TYPE = "cash_gap_threshold"
+
+#: 默认阈值（万元）—— 与改前硬编码常量逐字一致
+DEFAULT_WARNING = 20.0
+DEFAULT_CRITICAL = 10.0
+
+PARAM_KEYS = ("warning", "critical")
+
+
+def _as_float(value: Any) -> Optional[float]:
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return None
+
+
+def validate_params(params: Any) -> Optional[str]:
+    """校验阈值参数；合法返回 None，非法返回中文错误信息（供 API 层直接回 400）。"""
+    if not isinstance(params, dict):
+        return "params 必须是对象，形如 {\"warning\": 20.0, \"critical\": 10.0}（单位：万元）"
+    warning = _as_float(params.get("warning"))
+    critical = _as_float(params.get("critical"))
+    if warning is None or critical is None:
+        return "params 必须同时包含数值型 warning 与 critical（单位：万元）"
+    if warning <= 0 or critical <= 0:
+        return "warning / critical 必须大于 0（单位：万元）"
+    if critical > warning:
+        return "critical（红灯线）不得高于 warning（黄灯线）"
+    return None
+
+
+def parse_params(params: Any) -> Optional[Tuple[float, float]]:
+    """解析参数 → (warning, critical)；非法返回 None（调用方回落默认值）。"""
+    if validate_params(params) is not None:
+        return None
+    return float(params["warning"]), float(params["critical"])
+
+
+def get_cash_gap_thresholds(db, entity_id: int) -> Tuple[float, float]:
+    """读取账套资金缺口阈值；无配置/非法/异常 → 默认 (20.0, 10.0)。
+
+    · 只认 enabled=1、最新 id 的一行（同一账套多行时以最新为准，不累加）
+    · 任何异常都不上抛：预警不能因为配置表读失败而消失（fail-safe）
+    """
+    try:
+        from app.api.alert_rules import AlertRule  # 延迟导入，避免 engine ↔ api 循环
+
+        rule = (
+            db.query(AlertRule)
+            .filter(
+                AlertRule.entity_id == int(entity_id),
+                AlertRule.rule_type == CASH_GAP_RULE_TYPE,
+                AlertRule.enabled == 1,
+            )
+            .order_by(AlertRule.id.desc())
+            .first()
+        )
+        if rule is None:
+            return DEFAULT_WARNING, DEFAULT_CRITICAL
+        params = rule.params
+        if isinstance(params, str):
+            import json
+
+            try:
+                params = json.loads(params)
+            except ValueError:
+                logger.warning("资金阈值配置 params 非合法 JSON（rule_id=%s）→ 回落默认值", rule.id)
+                return DEFAULT_WARNING, DEFAULT_CRITICAL
+        parsed = parse_params(params)
+        if parsed is None:
+            logger.warning("资金阈值配置参数非法（rule_id=%s params=%r）→ 回落默认值", rule.id, params)
+            return DEFAULT_WARNING, DEFAULT_CRITICAL
+        return parsed
+    except Exception as exc:  # noqa: BLE001 — 配置读取失败不得使预警整体失效
+        logger.warning("读取资金阈值配置失败（entity_id=%s）：%s → 回落默认值", entity_id, exc)
+        return DEFAULT_WARNING, DEFAULT_CRITICAL
+
+
+def describe_source(db, entity_id: int) -> Dict[str, Any]:
+    """取证用：说明本次阈值来自「配置」还是「默认」，便于回执与页面标注。"""
+    try:
+        from app.api.alert_rules import AlertRule
+
+        rule = (
+            db.query(AlertRule)
+            .filter(
+                AlertRule.entity_id == int(entity_id),
+                AlertRule.rule_type == CASH_GAP_RULE_TYPE,
+                AlertRule.enabled == 1,
+            )
+            .order_by(AlertRule.id.desc())
+            .first()
+        )
+        if rule is not None and parse_params(rule.params) is not None:
+            return {"source": "alert_rules", "rule_id": rule.id,
+                    "params": rule.params, "entity_id": int(entity_id)}
+    except Exception as exc:  # noqa: BLE001
+        logger.warning("读取资金阈值来源失败：%s", exc)
+    return {"source": "default", "rule_id": None,
+            "params": {"warning": DEFAULT_WARNING, "critical": DEFAULT_CRITICAL},
+            "entity_id": int(entity_id) if entity_id is not None else None}