fix(kpi): 阈值红黄绿读写/填写规则修复 — 统一解析器+红灯优先+建议可解析+前端校验+存量修正 (project-20260911-threshold-fix)

① 新建 app/utils/threshold_parser.py 统一解析/判定（单一事实源）：
   - 支持负数（>=-100000）、闭区间 A~B、多条件 C1|C2；空串=未设置
   - 判定顺序 red→green→yellow：红灯优先（消除宽黄灯遮蔽红灯），
     green 先于 yellow（green 是主条件，yellow 是更宽兜底带）
② kpis.py / alert_generator.py 双实现收敛到统一解析器（消除重复维护）
③ thresholds.py suggest 输出可解析表达式（原黄色/适中型生成 `52.33~107.67`、`偏离55%` 等
   区间/文字 → 用户点"自动建议"填入后静默失效；另修复大数目标生成 1.6e+06 科学计数法）
④ KPIDetail.vue 三个阈值输入加 placeholder/tooltip/帮助文案 + 保存前格式校验（非法即拒）
⑤ 存量 4 个不可解析表达式修正（id=46 C_REBATE_RATE / id=327 BH_SALES_10），
   改前 mysqldump 备份 backend/scripts/backups/kpi_definitions.bak-20260911.sql +
   threshold_rows_before_20260911.json（可回滚）；不可解析 5→0
⑥ 单测 97 条 + 红黄绿判定回归 367 判定点（旧→新差异 14 条，含差异说明）

backend/tests/test_threshold_parser_20260911.py

@@ -0,0 +1,263 @@
+# -*- coding: utf-8 -*-
+"""统一阈值解析器 + 红黄绿判定顺序（红灯优先）单测
+
+任务：project-20260911-threshold-fix
+覆盖：解析器（正/负/小数/区间/多条件/非法）、判定顺序、双调用方接线、存量表达式回归。
+"""
+import os
+import sys
+
+import pytest
+
+BACKEND = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+if BACKEND not in sys.path:
+    sys.path.insert(0, BACKEND)
+
+from app.utils.threshold_parser import (  # noqa: E402
+    LEVEL_PRIORITY,
+    calc_level,
+    calc_level_from_exprs,
+    describe_level,
+    eval_threshold,
+    is_valid_threshold,
+    parse_clauses,
+    parse_threshold,
+)
+
+
+class _Kpi:
+    """轻量替身：只需要 3 个阈值属性"""
+
+    def __init__(self, g=None, y=None, r=None):
+        self.threshold_green = g
+        self.threshold_yellow = y
+        self.threshold_red = r
+
+
+# ───────────────────────── ① 解析器 ─────────────────────────
+
+@pytest.mark.parametrize("expr,expected", [
+    (">=800", (">=", 800.0)),
+    ("<=25", ("<=", 25.0)),
+    (">60", (">", 60.0)),
+    ("<20", ("<", 20.0)),
+    ("=100", ("=", 100.0)),
+    ("!=0", ("!=", 0.0)),
+    (">=-100000", (">=", -100000.0)),      # 缺陷3：负数
+    ("<-100000", ("<", -100000.0)),
+    ("<-1.5", ("<", -1.5)),
+    (">=1.0", (">=", 1.0)),
+    (">= 800", (">=", 800.0)),              # 允许空白
+    ("   >=800  ", (">=", 800.0)),
+    ("52.33~107.67", ("~", (52.33, 107.67))),  # 区间
+    ("-182678~183078", ("~", (-182678.0, 183078.0))),
+])
+def test_parse_threshold_ok(expr, expected):
+    assert parse_threshold(expr) == expected
+
+
+@pytest.mark.parametrize("expr", ["偏离55%", "偏离>55%", "80%", ">=abc", "~", ">=", "52.33~",
+                                  ">=1>=2", "abc", ">=800元", ">=- 100"])
+def test_parse_threshold_invalid(expr):
+    assert parse_threshold(expr) == (None, None)
+    assert is_valid_threshold(expr) is False
+
+
+@pytest.mark.parametrize("expr", [None, "", "   "])
+def test_blank_is_valid_but_no_clause(expr):
+    """空串 = 不设置阈值：视为合法，但无子句。"""
+    assert is_valid_threshold(expr) is True
+    assert parse_clauses(expr) == []
+    assert parse_threshold(expr) == (None, None)
+
+
+def test_multi_clause():
+    assert is_valid_threshold("<=36|>=124") is True
+    assert is_valid_threshold("<=36 | >=124") is True
+    assert is_valid_threshold("<=36｜>=124") is True   # 全角竖线
+    assert is_valid_threshold("<=36|abc") is False
+    assert parse_clauses("<=36|>=124") == [("<=", 36.0), (">=", 124.0)]
+
+
+@pytest.mark.parametrize("actual,expr,expected", [
+    (800, ">=800", True), (799.99, ">=800", False),
+    (25, "<=25", True), (25.01, "<=25", False),
+    (61, ">60", True), (60, ">60", False),
+    (19, "<20", True), (20, "<20", False),
+    (-100000, ">=-100000", True), (-100001, ">=-100000", False),
+    (-100001, "<-100000", True),
+    (80, "52.33~107.67", True), (52.33, "52.33~107.67", True),
+    (107.67, "52.33~107.67", True), (107.68, "52.33~107.67", False),
+    (200, "<24.66|>135.34", True), (10, "<24.66|>135.34", True),
+    (80, "<24.66|>135.34", False),
+    (None, ">=0", False),
+    (5, "偏离55%", False),      # 非法表达式 → 不命中（不静默乱判）
+    (5, "", False),
+])
+def test_eval_threshold(actual, expr, expected):
+    assert eval_threshold(actual, expr) is expected
+
+
+# ─────────────────── ② 判定顺序：红灯优先 ───────────────────
+
+def test_level_priority_is_red_first():
+    assert LEVEL_PRIORITY == ("red", "green", "yellow")
+
+
+def test_defect5_yellow_no_longer_masks_red():
+    """缺陷5 实测：id=6 G='<=76' Y='>76' R='>91'，值 95 必须判红（原来判黄）。"""
+    kpi = _Kpi(g="<=76", y=">76", r=">91")
+    assert calc_level(95, kpi) == "red"      # 关键用例
+    assert calc_level(92, kpi) == "red"
+    assert calc_level(91, kpi) == "yellow"   # 未过 >91 → 黄
+    assert calc_level(80, kpi) == "yellow"
+    assert calc_level(76, kpi) == "green"    # <=76 → 绿
+    assert calc_level(70, kpi) == "green"
+
+
+def test_green_beats_wide_yellow():
+    """id=1 实测：G='>=800' Y='>=700'，值 900 不能判黄。"""
+    kpi = _Kpi(g=">=800", y=">=700", r="<600")
+    assert calc_level(900, kpi) == "green"
+    assert calc_level(750, kpi) == "yellow"
+    assert calc_level(500, kpi) == "red"
+    assert calc_level(650, kpi) == "info"    # 600~700 无命中
+
+
+def test_negative_thresholds():
+    """id=32：Y='>=-100000' R='<-100000' 存量负数表达式（缺陷3）。"""
+    kpi = _Kpi(g=">=0", y=">=-100000", r="<-100000")
+    assert calc_level(100, kpi) == "green"
+    assert calc_level(-50000, kpi) == "yellow"
+    assert calc_level(-200000, kpi) == "red"
+
+
+def test_moderate_range_semantics():
+    """区间型（middle_best）：绿内区间 → 黄外环 → 红区间外。"""
+    kpi = _Kpi(g="52.33~107.67", y="24.66~135.34", r="<24.66|>135.34")
+    assert calc_level(80, kpi) == "green"
+    assert calc_level(52.8, kpi) == "green"
+    assert calc_level(124.1, kpi) == "yellow"
+    assert calc_level(30, kpi) == "yellow"
+    assert calc_level(200, kpi) == "red"
+    assert calc_level(10, kpi) == "red"
+
+
+def test_no_threshold_and_none_actual():
+    assert calc_level(100, _Kpi()) == "info"
+    assert calc_level(None, _Kpi(g=">=0", y=">=0", r=">=0")) == "info"
+    assert calc_level_from_exprs(50, green=None, yellow=None, red=None) == "info"
+
+
+def test_describe_level():
+    kpi = _Kpi(g="<=76", y=">76", r=">91")
+    assert describe_level(95, kpi) == ("red", ">91")
+    assert describe_level(80, kpi) == ("yellow", ">76")
+    assert describe_level(70, kpi) == ("green", "<=76")
+    assert describe_level(0, kpi) == ("green", "<=76")
+    assert describe_level(None, kpi) == ("info", None)
+
+
+# ─────────────────── ③ 双调用方接线（消除双实现） ───────────────────
+
+def test_alert_generator_uses_unified_parser():
+    """alert_generator 必须委托统一解析器（负数/区间/多条件都生效）。"""
+    from scripts import alert_generator as ag
+
+    assert ag._parse_threshold(">=-100000") == (">=", -100000.0)
+    assert ag._parse_threshold("52.33~107.67") == ("~", (52.33, 107.67))
+
+    trig, msg = ag._check_threshold(95, ">91", "red")
+    assert trig is True and ">91" in msg
+    assert ag._check_threshold(95, ">91x", "red") == (False, "")
+    assert ag._check_threshold(None, ">91", "red") == (False, "")
+    # 区间 + 多条件（旧实现做不到）
+    assert ag._check_threshold(124.1, "24.66~135.34", "yellow")[0] is True
+    assert ag._check_threshold(10, "<24.66|>135.34", "red")[0] is True
+
+
+def test_alert_generator_loop_order_is_red_first():
+    """判定循环顺序必须与 LEVEL_PRIORITY 一致（红灯优先）。"""
+    import inspect
+    from scripts import alert_generator as ag
+
+    src = inspect.getsource(ag.run_alert_check)
+    assert "for level in LEVEL_PRIORITY" in src
+    assert 'for level in ["green", "yellow", "red"]' not in src
+
+
+def test_kpis_static_threshold_level_uses_unified_parser():
+    from app.api.kpis import _static_threshold_level
+
+    kpi = _Kpi(g=">=0", y=">=-100000", r="<-100000")
+    assert _static_threshold_level(-200000, kpi) == "red"
+    assert _static_threshold_level(-50000, kpi) == "yellow"
+    assert _static_threshold_level(100, kpi) == "green"
+
+
+def test_kpis_validate_threshold_format():
+    from app.api.kpis import validate_threshold_format
+
+    assert validate_threshold_format({}) == []
+    assert validate_threshold_format({"threshold_green": ">=800", "threshold_yellow": "",
+                                      "threshold_red": None}) == []
+    errs = validate_threshold_format({"threshold_yellow": "偏离55%"})
+    assert len(errs) == 1 and "threshold_yellow" in errs[0]
+    errs2 = validate_threshold_format({"threshold_green": "80%", "threshold_red": "偏离>55%"})
+    assert len(errs2) == 2
+
+
+def test_suggest_labels_are_parseable():
+    """suggest 生成的 label 必须可解析（缺陷1 根因）。"""
+    from app.api import thresholds as th
+
+    def _walk(obj, acc):
+        if isinstance(obj, dict):
+            if "label" in obj and obj.get("label") is not None:
+                acc.append(obj["label"])
+            for v in obj.values():
+                _walk(v, acc)
+        elif isinstance(obj, list):
+            for v in obj:
+                _walk(v, acc)
+
+    class _K:
+        def __init__(self, code, target):
+            self.id = 1
+            self.kpi_code = code
+            self.kpi_name = code
+            self.target_value = target
+
+    for code in ("SALES_TOTAL", "COST_CONTROL_RATE", "TOP5_CUSTOMER_RATIO", "MADE_UP_CODE"):
+        out = th.suggest_by_type(_K(code, 80.0))
+        labels = []
+        _walk(out, labels)
+        assert labels, code
+        for lb in labels:
+            assert is_valid_threshold(lb), f"{code} 生成了不可解析 label: {lb!r}"
+
+
+def test_existing_266_expressions_still_parse():
+    """回归：库里现存的表达式语法必须全部可解析（除已修正的存量 4 条外为 0 不可解析）。"""
+    from app.database import get_session_local
+    from app.models import KPIDefinition
+
+    try:
+        db = get_session_local()()
+    except Exception as e:  # 无DB环境（CI）时跳过
+        pytest.skip(f"DB 不可用: {e}")
+    try:
+        rows = db.query(KPIDefinition).filter(
+            (KPIDefinition.threshold_green.isnot(None)) |
+            (KPIDefinition.threshold_yellow.isnot(None)) |
+            (KPIDefinition.threshold_red.isnot(None))
+        ).all()
+        bad = []
+        for k in rows:
+            for f in ("threshold_green", "threshold_yellow", "threshold_red"):
+                e = getattr(k, f)
+                if e and str(e).strip() and not is_valid_threshold(e):
+                    bad.append((k.id, k.kpi_code, f, str(e)))
+        assert bad == [], f"仍存在不可解析阈值: {bad}"
+    finally:
+        db.close()