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/tenancy/static/admin/js/merchant-detail.js

@@ -16,6 +16,10 @@ function adminMerchantDetail() {
         error: null,
         merchantId: null,
 
+        // Modal state
+        showDeleteMerchantModal: false,
+        showDeleteMerchantFinalModal: false,
+
         // Subscription state
         platforms: [],
         subscriptions: [],
@@ -239,8 +243,8 @@ function adminMerchantDetail() {
             return formatted;
         },
 
-        // Delete merchant
-        async deleteMerchant() {
+        // Prompt delete merchant (first step of double confirm)
+        promptDeleteMerchant() {
             merchantDetailLog.info('Delete merchant requested:', this.merchantId);
 
             if (this.merchant?.store_count > 0) {
@@ -248,17 +252,16 @@ function adminMerchantDetail() {
                 return;
             }
 
-            if (!confirm(`Are you sure you want to delete merchant "${this.merchant.name}"?\n\nThis action cannot be undone.`)) {
-                merchantDetailLog.info('Delete cancelled by user');
-                return;
-            }
+            this.showDeleteMerchantModal = true;
+        },
 
-            // Second confirmation for safety
-            if (!confirm(`FINAL CONFIRMATION\n\nAre you absolutely sure you want to delete "${this.merchant.name}"?`)) {
-                merchantDetailLog.info('Delete cancelled by user (second confirmation)');
-                return;
-            }
+        // Confirm first step, show final confirmation
+        confirmDeleteMerchantStep() {
+            this.showDeleteMerchantFinalModal = true;
+        },
 
+        // Delete merchant
+        async deleteMerchant() {
             try {
                 const url = `/admin/merchants/${this.merchantId}?confirm=true`;
                 window.LogConfig.logApiCall('DELETE', url, null, 'request');