fix(admin): remove employees.tsx layout wrapper — breaks nested routing

Deleting employees.tsx allows employees/index.tsx to serve /admin/employees
directly (same pattern as roles/), fixing the blank page regression.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/admin/employees.tsx

@@ -1,6 +0,0 @@
-import { Outlet } from '@solidjs/router';
-
-// Layout wrapper — actual pages are in employees/index.tsx and employees/create.tsx
-export default function EmployeesLayout() {
-  return <Outlet />;
-}