fix(settings): persist every SMS template variable on save

Mongoose Mixed updates were dropping extra invoiceCreated variables after a successful save.

components/settings/smsTemplates.test.js

@@ -0,0 +1,61 @@
+'use strict';
+
+const { describe, it } = require('node:test');
+const assert = require('node:assert/strict');
+const {
+  SMS_TEMPLATE_DEFS,
+  normalizeStoredEntry,
+  resolveVariablesList,
+  parseIncomingVariables,
+  mergeTemplateEntry
+} = require('./smsTemplates');
+
+const invoiceDef = SMS_TEMPLATE_DEFS.find((def) => def.key === 'invoiceCreated');
+
+const threeInvoiceVars = [
+  { slot: 'amount', name: 'PAYMENT_PRICE' },
+  { slot: 'fullName', name: 'FULLNAME' },
+  { slot: 'course', name: 'COURSE' }
+];
+
+describe('SMS template variables', () => {
+  it('keeps all invoiceCreated variables when stored as an array', () => {
+    const stored = normalizeStoredEntry({
+      templateId: '111',
+      variables: threeInvoiceVars
+    }, invoiceDef);
+    const resolved = resolveVariablesList(invoiceDef, stored.variables);
+
+    assert.equal(resolved.length, 3);
+    assert.deepEqual(resolved.map((item) => item.slot), ['amount', 'fullName', 'course']);
+    assert.deepEqual(resolved.map((item) => item.name), ['PAYMENT_PRICE', 'FULLNAME', 'COURSE']);
+  });
+
+  it('keeps all invoiceCreated variables when an array was stored as a numeric object', () => {
+    const stored = normalizeStoredEntry({
+      templateId: '111',
+      variables: {
+        0: { slot: 'amount', name: 'PAYMENT_PRICE' },
+        1: { slot: 'fullName', name: 'FULLNAME' },
+        2: { slot: 'course', name: 'COURSE' }
+      }
+    }, invoiceDef);
+    const resolved = resolveVariablesList(invoiceDef, stored.variables);
+
+    assert.equal(resolved.length, 3);
+    assert.deepEqual(resolved.map((item) => item.slot), ['amount', 'fullName', 'course']);
+  });
+
+  it('replaces a legacy single-slot map with every incoming invoiceCreated variable', () => {
+    const incoming = parseIncomingVariables(threeInvoiceVars, invoiceDef);
+    const merged = mergeTemplateEntry(
+      invoiceDef,
+      { templateId: '111', variables: { amount: 'PAYMENT_PRICE' } },
+      { templateId: '111', variables: incoming }
+    );
+
+    assert.equal(merged.variables.length, 3);
+    assert.deepEqual(merged.variables.map((item) => item.slot), ['amount', 'fullName', 'course']);
+    assert.deepEqual(merged.variables.map((item) => item.name), ['PAYMENT_PRICE', 'FULLNAME', 'COURSE']);
+  });
+});