fix(zipcode): cap table width in dialog to half screen via optional maxWidthCap; pass 0.5 fraction when used in Company/Warehouse dialogs

- ZipcodeTable: add maxWidthCap and use min(viewport, cap) to compute width
- ZipcodeSearchScreen: allow tableMaxWidthFraction and forward to table
- Apply 0.5 in CompanyForm and WarehouseLocationForm dialogs

flutter analyze: 0 errors, warnings unaffected

lib/screens/warehouse_location/warehouse_location_form.dart

@@ -80,6 +80,7 @@ class _WarehouseLocationFormScreenState
                 GetIt.instance<ZipcodeUseCase>(),
               ),
               child: ZipcodeSearchScreen(
+                tableMaxWidthFraction: 0.5,
                 onSelect: (zipcode) {
                   Navigator.of(dialogContext).pop(zipcode);
                 },