增加建立新版本

bms-back/bms-system/src/main/java/com/bms/price/domain/PrcPriceSetVersion.java

@@ -29,7 +29,10 @@ public class PrcPriceSetVersion extends BaseEntity
     /** 0 draft / 3 pending / 1 active / 2 expired */
     private String status;
     /**
-     * Create-price mode for this version: PULL = from product library, IMPORT = Excel.
+     * Create-price mode for this version:
+     * PULL = from product library,
+     * IMPORT = Excel with prior version preload,
+     * IMPORT_FRESH = Excel without prior version data.
      * Column: price_build_mode
      */
     private String priceBuildMode;

bms-back/bms-system/src/main/java/com/bms/price/service/impl/PrcPriceSetServiceImpl.java

@@ -3361,9 +3361,10 @@ public class PrcPriceSetServiceImpl implements IPrcPriceSetService
     }
 
     /**
-     * Draft only: when priceBuildMode changes (PULL/IMPORT), delete this version's
+     * Draft only: when priceBuildMode changes (PULL/IMPORT/IMPORT_FRESH), delete this version's
      * product / detail / SALES surcharge rel rows. Same mode or non-draft: no-op.
      * IMPORT: after wipe, copy products+details from latest prior version (if any).
+     * IMPORT_FRESH: wipe only, do not copy prior version (blank Excel build).
      */
     private void clearDraftVersionChildrenIfBuildModeChanged(PrcPriceSetVersion db, PrcPriceSetVersion incoming)
     {
@@ -3387,6 +3388,7 @@ public class PrcPriceSetServiceImpl implements IPrcPriceSetService
         }
         Long psvId = db.getPsvId();
         wipeVersionChildren(psvId, db.getStatus());
+        // IMPORT inherits prior version; IMPORT_FRESH starts empty for Excel import
         if ("IMPORT".equalsIgnoreCase(newMode))
         {
             copyLatestPriorVersionChildren(db.getPriceSetId(), psvId);