fix(org): preserve group assignments when reordering pins

Fixes ReorderOrgPinnedRepos to only update display_order field, preserving existing group_id assignments. Uses MustCols to ensure zero values are properly updated (first item can have display_order=0). Previously, reordering would unintentionally clear group assignments.

models/organization/org_pinned.go

@@ -206,11 +206,12 @@ func ReorderOrgPinnedRepos(ctx context.Context, orgID int64, repoOrders []Pinned
 	defer committer.Close()
 
 	for _, order := range repoOrders {
+		// Use MustCols to ensure zero values are updated (display_order can be 0 for first item)
+		// Only update display_order, not group_id (preserve existing group assignments)
 		if _, err := db.GetEngine(ctx).
 			Where("org_id = ? AND repo_id = ?", orgID, order.RepoID).
-			Cols("group_id", "display_order").
+			MustCols("display_order").
 			Update(&OrgPinnedRepo{
-				GroupID:      order.GroupID,
 				DisplayOrder: order.DisplayOrder,
 			}); err != nil {
 			return err