Add saved payout destination UX and service contracts (#54)

frontend/app/lib/workspace/settings.dart

@@ -106,6 +106,15 @@ class SettingsPage extends StatelessWidget {
                 ),
               ),
               const SizedBox(height: 16),
+              Card(
+                child: ListTile(
+                  leading: const Icon(Icons.account_balance_outlined),
+                  title: Text(l.dTitle),
+                  trailing: const Icon(Icons.chevron_right),
+                  onTap: () => context.push('/settings/payout-methods'),
+                ),
+              ),
+              const SizedBox(height: 16),
               const SecuritySettings(),
               const SizedBox(height: 20),
               TextButton(