fix: replace all native confirm() dialogs with styled modal macros

Migrated ~68 native browser confirm() calls across 74 files to use the
project's confirm_modal/confirm_modal_dynamic Jinja2 macros, providing
consistent styled confirmation dialogs instead of plain browser popups.

Modules updated: core, tenancy, cms, marketplace, messaging, billing,
customers, orders, cart. Uses danger/warning/info variants and
double-confirm pattern for destructive delete operations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/cms/static/store/js/media.js

@@ -105,6 +105,7 @@ function storeMedia() {
         // Modal states
         showUploadModal: false,
         showDetailModal: false,
+        showDeleteMediaConfirm: false,
         selectedMedia: null,
         editingMedia: {
             filename: '',
@@ -253,10 +254,6 @@ function storeMedia() {
         async deleteMedia() {
             if (!this.selectedMedia) return;
 
-            if (!confirm(I18n.t('cms.confirmations.delete_file'))) {
-                return;
-            }
-
             this.saving = true;
 
             try {