Simplify navigation and modernize profile and sign-in

frontend/app/ui/SettingsNavigation.tsx

@@ -0,0 +1,18 @@
+'use client'
+
+import { usePathname, useRouter } from 'next/navigation'
+import { CONFIG_GROUPS } from '../admin/configNavigation'
+
+export default function SettingsNavigation() {
+  const pathname = usePathname()
+  const router = useRouter()
+  const current = CONFIG_GROUPS.flatMap((group) => group.items).find((item) => item.href === pathname)
+  if (pathname === '/admin') return null
+  return <nav className="settings-top-navigation" aria-label="Settings navigation">
+    <a href="/admin">← All settings</a>
+    <label><span>Jump to</span><select aria-label="Settings section" value={current?.href ?? '/admin'} onChange={(event) => router.push(event.target.value)}>
+      <option value="/admin">Settings overview</option>
+      {CONFIG_GROUPS.map((group) => <optgroup label={group.title} key={group.title}>{group.items.map((item) => <option key={item.href} value={item.href}>{item.label}</option>)}</optgroup>)}
+    </select></label>
+  </nav>
+}