admin-panel: add shared modal/header/icon/delete-handler components

New src/components/common/:
- BaseFormModal.vue — the standard shell every converted add/edit modal will
  use: header=title, footer=buttons, body=form. Replaces the ad-hoc
  60%/70%/80% <a-modal> widths used across the codebase with 4 named sizes.
- ListPageHeader.vue — the add button that goes above every list page,
  gated on the same rid the create route used (modelled on the one place
  this already existed, ListUser.vue's add-user button).

New src/components/icons.ts: the legacy-Feather-name -> ant-icon map,
extracted out of TooltipBtn.vue so the sidebar can resolve the same names
through the same map instead of a second copy.

New src/composables/useDeleteHandler.ts: the delete-then-refetch-then-toast
handler that was copy-pasted verbatim in 6 list views (city/cityList.vue,
user/ListUser.vue, apps/category/List.vue, finical/list.vue,
apps/product/ProductList.vue, manage/Const.vue). Preserves each site's exact
success-message wording and message.success/info choice, and ProductList's
irregular POST-based delete endpoint.

Verified: pnpm build passes.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/admin-panel/src/views/city/cityList.vue

@@ -25,7 +25,7 @@
               placement="top"
               ok-text="بله"
               cancel-text="خیر"
-              @confirm="confirmDelete(record.id)"
+              @confirm="confirmDelete(`cities/${record.id}`)"
             >
               <template #title><p>آیا مطمئن به حذف شهر مورد نظر هستید ؟</p></template>
               <DeleteOutlined class="cursor-pointer mx-1 text-danger" />
@@ -53,11 +53,12 @@
 
 <script setup lang="ts">
 import { reactive, ref } from 'vue';
-import { message, Modal } from 'ant-design-vue';
+import { message } from 'ant-design-vue';
 import { DeleteOutlined, EditOutlined } from '@ant-design/icons-vue';
 import XTable from '../../components/x-table/XTable.vue';
 import { buildCityListModel } from './CityListModel';
 import { useUsersStore } from '../../stores/users';
+import { useDeleteHandler } from '../../composables/useDeleteHandler';
 import api from '../../api/client';
 
 const users = useUsersStore();
@@ -106,15 +107,11 @@ async function save() {
   }
 }
 
-async function confirmDelete(id: string) {
-  try {
-    await api.delete(`cities/${id}`);
-    message.success('شهر حذف شد');
-    citiesTable.value?.fetch();
-  } catch (e: any) {
-    // The backend refuses while customers, branches or addresses reference it.
-    Modal.error({ title: e?.response?.data?.message ?? 'خطا در حذف شهر', okText: 'بستن' });
-  }
-}
+// The backend refuses while customers, branches or addresses reference it.
+const { remove: confirmDelete } = useDeleteHandler({
+  onSuccess: () => citiesTable.value?.fetch(),
+  successMessage: 'شهر حذف شد',
+  fallbackErrorMessage: 'خطا در حذف شهر',
+});
 </script>