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/messaging/static/admin/js/messages.js

@@ -49,6 +49,9 @@ function adminMessages(initialConversationId = null) {
         replyContent: '',
         attachedFiles: [],
 
+        // Close conversation confirm state
+        showCloseConversationConfirm: false,
+
         // Compose modal
         showComposeModal: false,
         compose: {
@@ -304,8 +307,6 @@ function adminMessages(initialConversationId = null) {
          * Close conversation
          */
         async closeConversation() {
-            if (!confirm(I18n.t('messaging.confirmations.close_conversation_admin'))) return;
-
             try {
                 await apiClient.post(`/admin/messages/${this.selectedConversationId}/close`);