fix(client): refine T-103 prefix diagnostics

client/src/cmbuyer_client/device/sku_evidence_sanitizer.py

@@ -423,8 +423,10 @@ def _crossing_price_text_mismatch_reason(text: str) -> str:
         return "non_ascii_whitespace"
     if any(marker in text for marker in ("提交订单", "支付", "下单", "优惠")):
         return "extra_or_order"
-    without_leading_space = text.lstrip(" ")
+    without_one_leading_space = text[1:] if text.startswith(" ") else text
-    if without_leading_space.startswith("快") and not without_leading_space.startswith("快卖光"):
+    if without_one_leading_space.startswith("快要抢光"):
+        return "observed_prefix_kuaiyaoqiangguang"
+    if without_one_leading_space.startswith("快") and not without_one_leading_space.startswith("快卖光"):
         return "known_prefix_missing"
     if "¥" not in text and "￥" not in text:
         return "currency_missing"

client/tests/device/test_sku_evidence_sanitizer.py

@@ -289,6 +289,12 @@ class SkuEvidenceSanitizerTests(unittest.TestCase):
             (
                 "known-prefix-missing",
                 _xml_with_prices(current="快要抢光 ¥12.88"),
+                "observed_prefix_kuaiyaoqiangguang",
+                PRICE_CURRENT_BOUNDS,
+            ),
+            (
+                "other-kuai-prefix-remains-generic",
+                _xml_with_prices(current="快递地址 ¥12.88"),
                 "known_prefix_missing",
                 PRICE_CURRENT_BOUNDS,
             ),
@@ -354,6 +360,23 @@ class SkuEvidenceSanitizerTests(unittest.TestCase):
                 for raw_fragment in (TEST_ADDRESS, FULL_PHONE, "使用微信支付", "提交订单", "¥12.88"):
                     self.assertNotIn(raw_fragment, message)
 
+    def test_observed_prefix_diagnostic_does_not_echo_its_suffix(self) -> None:
+        suffix = "地址和金额都不得回显"
+        text = f"快要抢光 ¥12.88 {suffix}"
+        with TemporaryDirectory() as temporary:
+            raw = _write_raw(Path(temporary), xml=_xml_with_prices(current=text))
+            with self.assertRaises(SkuEvidenceSanitizationError) as raised:
+                sanitize_sku_panel_evidence(raw, raw.parent / "derived")
+
+            message = str(raised.exception)
+            self.assertEqual(
+                message,
+                "跨界价格节点文本不匹配：slot=[396,503][712,570]；"
+                "reason=observed_prefix_kuaiyaoqiangguang。",
+            )
+            self.assertNotIn(suffix, message)
+            self.assertNotIn("¥12.88", message)
+
     def test_crossing_price_projection_allows_only_limited_ascii_spaces_and_yen_variants(self) -> None:
         for current in ("快卖光 ¥12.88", " 快卖光 ¥ 12.88 ", "快卖光 ￥12.88"):
             with self.subTest(current=current), TemporaryDirectory() as temporary: