feat(ext/vault): wire renderSettings / teardownSettings from settings component

extension/src/popup/components/settings.ts

@@ -189,3 +189,8 @@ async function renderDisplaySection(): Promise<void> {
     updateSwatch(swatch, DEFAULT_DIGIT_COLOR, DEFAULT_SYMBOL_COLOR);
   });
 }
+
+// DEV-B interface contract stub — will be replaced with real teardown logic at merge time
+export function teardownSettings(): void {
+  // no-op stub
+}

extension/src/vault/vault.ts

@@ -19,7 +19,7 @@ import { renderItemDetail } from '../popup/components/item-detail';
 import { renderItemForm } from '../popup/components/item-form';
 import { renderTrash, teardown as teardownTrash } from '../popup/components/trash';
 import { renderDevices, teardown as teardownDevices } from '../popup/components/devices';
-import { renderSettings } from '../popup/components/settings';
+import { renderSettings, teardownSettings } from '../popup/components/settings';
 import { renderVaultSettings as renderVaultSettingsView } from '../popup/components/settings-vault';
 import { renderFieldHistory, teardown as teardownFieldHistory } from '../popup/components/field-history';
 import { renderBackupPanel, teardown as teardownBackup } from './components/backup-panel';
@@ -748,6 +748,7 @@ export const __test__ = { renderFormWrapped };
 function teardownPaneComponents(): void {
   teardownTrash();
   teardownDevices();
+  teardownSettings();
   teardownFieldHistory();
   teardownBackup();
   teardownImport();
@@ -797,7 +798,7 @@ function renderPane(): void {
       renderDevices(pane);
       break;
     case 'settings':
-      renderSettings(pane);
+      void renderSettings(pane);
       break;
     case 'settings-vault':
       renderVaultSettingsView(pane);