Add company/user filters to Requests, move Companies to bottom of nav

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

src/components/Layout.jsx

@@ -8,9 +8,9 @@ function TeamNav({ onNav }) {
       <div className="sidebar-section-label">Main</div>
       {[
         { to: '/dashboard', label: 'Dashboard' },
-        { to: '/companies', label: 'Companies' },
         { to: '/requests', label: 'Requests' },
         { to: '/invoices', label: 'Invoices' },
+        { to: '/companies', label: 'Companies' },
       ].map(({ to, label }) => (
         <NavLink key={to} to={to} onClick={onNav} className={({ isActive }) => `sidebar-link${isActive ? ' active' : ''}`}>
           {label}