Merge branch 'mysql' into dev

Resolved merge conflict in utils/material_status_validator.py by keeping
both deduplication statistics and error messages for empty results.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

gui/data_extraction_tab.py

@@ -176,7 +176,7 @@ class DataExtractionTab(ttk.Frame):
                 temp_file = f.name
                 f.write('\n'.join(production_ids))
 
-            from utils.离散备料计划维护数据提取 import DiscreteMaterialPlanExtractor
+            from utils.discrete_material_plan_extractor import DiscreteMaterialPlanExtractor
             self.extractor = DiscreteMaterialPlanExtractor(
                 username=self.config.get("erp.username"),
                 password=self.config.get("erp.password"),