fix(observability): router conflict, logout button, missing i18n

- Fix chi duplicate Route() panic by consolidating read/write routes
  into single Route blocks with nested admin Group
- Add logout button to sidebar with token cleanup
- Add missing settingsAuth.password i18n key

web/src/routes/+layout.svelte

@@ -6,7 +6,7 @@
 	import Toast from '$lib/components/Toast.svelte';
 	import ThemeToggle from '$lib/components/ThemeToggle.svelte';
 	import LocaleSwitcher from '$lib/components/LocaleSwitcher.svelte';
-	import { IconDashboard, IconProjects, IconDeploy, IconProxies, IconEvents, IconSettings, IconMenu, IconX } from '$lib/components/icons';
+	import { IconDashboard, IconProjects, IconDeploy, IconProxies, IconEvents, IconSettings, IconMenu, IconX, IconLogout } from '$lib/components/icons';
 	import { connectGlobalEvents, type SSEConnection } from '$lib/sse';
 	import { instanceStatusStore } from '$lib/stores/instance-status';
 	import { resolvedTheme, applyTheme } from '$lib/stores/theme';
@@ -58,6 +58,15 @@
 		sidebarOpen = false;
 	});
 
+	function logout() {
+		if (typeof localStorage !== 'undefined') {
+			localStorage.removeItem('auth_token');
+		}
+		sseConnection?.close();
+		sseConnection = null;
+		window.location.href = '/login';
+	}
+
 	onMount(() => {
 		sseConnection = connectGlobalEvents({
 			onInstanceStatus(payload) {
@@ -151,7 +160,17 @@
 				<ThemeToggle />
 				<LocaleSwitcher />
 			</div>
-			<p class="text-xs text-[var(--text-tertiary)]">{$t('app.name')} {$t('app.version')}</p>
+			<div class="flex items-center justify-between">
+				<p class="text-xs text-[var(--text-tertiary)]">{$t('app.name')} {$t('app.version')}</p>
+				<button
+					onclick={logout}
+					class="inline-flex items-center gap-1.5 rounded-md px-2 py-1 text-xs font-medium text-[var(--text-secondary)] transition-colors hover:bg-[var(--surface-card-hover)] hover:text-[var(--color-danger)]"
+					title={$t('nav.logout')}
+				>
+					<IconLogout size={14} />
+					{$t('nav.logout')}
+				</button>
+			</div>
 		</div>
 	</aside>