feat(ar): 逾期预警判据 G5——90-150 前池 5pp/10万 + 责任人点名优先（阶段B 受批面）

backend/app/services/ar_overdue_alert.py

@@ -55,7 +55,9 @@ def validate_params(params: Any) -> Optional[str]:
     except ar_caliber.CaliberError as e:
         return str(e)
     for key in ("red", "yellow"):
-        if not isinstance(params.get(key), dict):
+        # 2026-10-21 阶段B：G5 新参数形状为扁平键（share_90_150_* 等），red/yellow 分组可缺省；
+        # 存在则必须是对象（防误传标量导致阈值静默失效）。
+        if params.get(key) is not None and not isinstance(params.get(key), dict):
             return "params.%s 必须是对象（阈值分组）" % key
     for key in ("assignee_by_unit", "action_texts"):
         if key in params and params[key] is not None and not isinstance(params[key], dict):
@@ -403,7 +405,10 @@ def _level_mom(mom_pct: Optional[float], params: Dict[str, Any]) -> Optional[str
 def _level_customer(overdue_amt: Decimal, oldest_days: int, params: Dict[str, Any]) -> Optional[str]:
     red = params.get("red") or {}
     yellow = params.get("yellow") or {}
+    # 阶段B G5 扁平参数：顶层 single_overdue_amt_gt 优先（未配 red 分组时仍可判红线）
     red_amt = red.get("single_overdue_amt_gt")
+    if red_amt is None:
+        red_amt = params.get("single_overdue_amt_gt")
     red_min_days = red.get("single_overdue_min_days")
     if red_amt is not None and overdue_amt > _dec(red_amt):
         if red_min_days is None or oldest_days >= int(red_min_days):
@@ -586,38 +591,99 @@ def compute(
                    "count_mom_pct": (round(mom_pct, 6) if mom_pct is not None else None)},
                   msg, action)
 
-    # 聚合判据 3：150+ 档占比环比上升 ⇒ 账龄结构恶化（§6.1 新增红线 2）
-    share_150 = None
-    prev_share_150 = None
+    # 聚合判据 3：账龄结构恶化（G5 2026-10-21 裁定）
+    #   · 新判据（参数化）：90–150 天「前池」占比环比上升 ≥ rise_pp_min **且** 该档余额 ≥ amt_min（AND）
+    #   · 兼容旧参数：未配 share_90_150_rise_pp_min 时，沿用 150+ 占比环比上升（red.structure_worsen）
+    share_90_150 = None
+    prev_share_90_150 = None
+    amt_90_150 = None
+    prev_amt_90_150 = None
     if total > 0:
-        share_150 = float(sum((_dec(r.get("b_150p")) for r in rows), Decimal("0")) / total)
+        amt_90_150 = sum((_dec(r.get("b_90_120")) + _dec(r.get("b_120_150")) for r in rows),
+                         Decimal("0"))
+        share_90_150 = float(amt_90_150 / total)
     if prev_rows:
-        prev_total = sum((_dec(r.get("total_amt")) for r in prev_rows), Decimal("0"))
-        if prev_total > 0:
-            prev_share_150 = float(
-                sum((_dec(r.get("b_150p")) for r in prev_rows), Decimal("0")) / prev_total)
-    structure_on = bool(red_cfg.get("structure_worsen"))
-    if structure_on:
-        if share_150 is not None and prev_share_150 is not None and share_150 > prev_share_150:
+        prev_total_90150 = sum((_dec(r.get("total_amt")) for r in prev_rows), Decimal("0"))
+        prev_amt_90_150 = sum((_dec(r.get("b_90_120")) + _dec(r.get("b_120_150")) for r in prev_rows),
+                              Decimal("0"))
+        if prev_total_90150 > 0:
+            prev_share_90_150 = float(prev_amt_90_150 / prev_total_90150)
+
+    rise_pp_min = params.get("share_90_150_rise_pp_min")
+    amt_min_90_150 = params.get("share_90_150_amt_min")
+    if rise_pp_min is not None and amt_min_90_150 is not None:
+        delta_pp = None
+        if share_90_150 is not None and prev_share_90_150 is not None:
+            delta_pp = (share_90_150 - prev_share_90_150) * 100.0
+        hit_90150 = (
+            delta_pp is not None and delta_pp >= float(rise_pp_min)
+            and amt_90_150 is not None and amt_90_150 >= _dec(amt_min_90_150)
+        )
+        if hit_90150:
             action = _action_text(params, "red")
             msg = _clip(
-                "【应收账款逾期】%s 150+ 档占比 %s%%（上期 %s%%）环比上升 %+.2fpp，账龄结构恶化"
-                "｜建议：%s" % (period, _fmt_pct(share_150), _fmt_pct(prev_share_150),
-                               (share_150 - prev_share_150) * 100.0, action or "见规则配置")
+                "【应收账款逾期】%s 90–150 天档占比 %s%%（上期 %s%%）环比 %+.2fpp ≥ %gpp，"
+                "该档余额 ¥%s（≥¥%s），账龄前池恶化｜建议：%s"
+                % (period, _fmt_pct(share_90_150), _fmt_pct(prev_share_90_150), delta_pp,
+                   float(rise_pp_min), _fmt_money(amt_90_150), _fmt_money(_dec(amt_min_90_150)),
+                   action or "见规则配置")
             )
-            _push_agg("structure_150p", "red",
-                      {"share_150p": round(share_150, 6),
+            _push_agg("structure_90_150", "red",
+                      {"share_90_150": round(share_90_150, 6),
                        "prev_period": prev_period,
-                       "prev_share_150p": (round(prev_share_150, 6)
-                                           if prev_share_150 is not None else None),
-                       "delta_pp": round((share_150 - prev_share_150) * 100.0, 4)},
+                       "prev_share_90_150": (round(prev_share_90_150, 6)
+                                             if prev_share_90_150 is not None else None),
+                       "delta_pp": round(delta_pp, 4),
+                       "amt_90_150": _money(amt_90_150),
+                       "rise_pp_min": float(rise_pp_min),
+                       "amt_min": float(amt_min_90_150)},
                       msg, action)
         else:
             notes.append(
-                "150+ 占比：本期 %s%% / 上期 %s%% ⇒ 结构恶化判据未触发"
-                % (_fmt_pct(share_150), _fmt_pct(prev_share_150)))
-    metrics["share_150p"] = (round(share_150, 6) if share_150 is not None else None)
-    metrics["prev_share_150p"] = (round(prev_share_150, 6) if prev_share_150 is not None else None)
+                "90–150 档：本期 %s%% / 上期 %s%%（Δ=%spp，门槛 ≥%gpp）｜余额 ¥%s（门槛 ≥¥%s）"
+                "⇒ 结构恶化判据未触发"
+                % (_fmt_pct(share_90_150), _fmt_pct(prev_share_90_150),
+                   ("%+.2f" % delta_pp) if delta_pp is not None else "-",
+                   float(rise_pp_min),
+                   _fmt_money(amt_90_150) if amt_90_150 is not None else "-",
+                   _fmt_money(_dec(amt_min_90_150))))
+        metrics["share_90_150"] = (round(share_90_150, 6) if share_90_150 is not None else None)
+        metrics["prev_share_90_150"] = (round(prev_share_90_150, 6)
+                                        if prev_share_90_150 is not None else None)
+        metrics["amt_90_150"] = (_money(amt_90_150) if amt_90_150 is not None else None)
+    else:
+        share_150 = None
+        prev_share_150 = None
+        if total > 0:
+            share_150 = float(sum((_dec(r.get("b_150p")) for r in rows), Decimal("0")) / total)
+        if prev_rows:
+            prev_total = sum((_dec(r.get("total_amt")) for r in prev_rows), Decimal("0"))
+            if prev_total > 0:
+                prev_share_150 = float(
+                    sum((_dec(r.get("b_150p")) for r in prev_rows), Decimal("0")) / prev_total)
+        structure_on = bool(red_cfg.get("structure_worsen"))
+        if structure_on:
+            if share_150 is not None and prev_share_150 is not None and share_150 > prev_share_150:
+                action = _action_text(params, "red")
+                msg = _clip(
+                    "【应收账款逾期】%s 150+ 档占比 %s%%（上期 %s%%）环比上升 %+.2fpp，账龄结构恶化"
+                    "｜建议：%s" % (period, _fmt_pct(share_150), _fmt_pct(prev_share_150),
+                                   (share_150 - prev_share_150) * 100.0, action or "见规则配置")
+                )
+                _push_agg("structure_150p", "red",
+                          {"share_150p": round(share_150, 6),
+                           "prev_period": prev_period,
+                           "prev_share_150p": (round(prev_share_150, 6)
+                                               if prev_share_150 is not None else None),
+                           "delta_pp": round((share_150 - prev_share_150) * 100.0, 4)},
+                          msg, action)
+            else:
+                notes.append(
+                    "150+ 占比：本期 %s%% / 上期 %s%% ⇒ 结构恶化判据未触发"
+                    % (_fmt_pct(share_150), _fmt_pct(prev_share_150)))
+        metrics["share_150p"] = (round(share_150, 6) if share_150 is not None else None)
+        metrics["prev_share_150p"] = (round(prev_share_150, 6)
+                                      if prev_share_150 is not None else None)
 
     # ── 逐户：assignee 派生失败 ⇒ 不生成（进 skipped[]），禁落空 assignee ──
     for c in customers: