fix: 校验采购尺码候选边界 (#256)

client/src/pdd_u2_purchase_adapter.py

@@ -1168,6 +1168,8 @@ class U2PddPurchaseAdapter(PddPurchaseAdapter):
                 diagnostics={"selection_failure": "target_not_visible"},
             )
 
+        self._validate_size_candidate_dimension(dimension)
+
         available_values = tuple(
             item for item in dimension.values if item.available
         )
@@ -1213,6 +1215,39 @@ class U2PddPurchaseAdapter(PddPurchaseAdapter):
         )
         raise PddPurchaseSpecResolutionRequired(snapshot)
 
+    @staticmethod
+    def _validate_size_candidate_dimension(dimension: SpecDimension) -> None:
+        """候选进入快照前满足 #254 的数量、文字和维度边界。"""
+
+        def valid_text(value: str) -> bool:
+            return (
+                1 <= len(value) <= 191
+                and not any(ord(char) < 32 or 127 <= ord(char) <= 159 for char in value)
+            )
+
+        texts = [item.text for item in dimension.values]
+        available_count = sum(item.available for item in dimension.values)
+        invalid_reason = ""
+        if dimension.key != "size" or not valid_text(dimension.name):
+            invalid_reason = "dimension_invalid"
+        elif len(set(texts)) != len(texts):
+            invalid_reason = "candidate_duplicated"
+        elif any(not valid_text(text) for text in texts):
+            invalid_reason = "candidate_text_invalid"
+        elif available_count > 100:
+            invalid_reason = "candidate_count_exceeded"
+        if invalid_reason:
+            raise PddPurchaseError(
+                "PURCHASE_SIZE_CANDIDATE_SCAN_INCOMPLETE",
+                "完整尺码候选不符合规格解析边界，已停止采购",
+                step="purchase_select_options",
+                diagnostics={
+                    "selection_failure": "target_not_visible",
+                    "candidate_validation": invalid_reason,
+                    "candidate_count": available_count,
+                },
+            )
+
     def _collect_size_candidates(self, device: Any) -> Optional[SpecDimension]:
         """使用采集模块同一套第二规格遍历，不建立新连接也不保存 XML。"""