feat(phase3): PWA, auto-discovery, bookmarklet, multi-tab sync

- PWA: manifest, service worker (cache-first static, network-first API),
  offline page, install prompt banner
- Auto-discovery: Docker socket + Traefik API scanning, approval UI
- Quick-add bookmarklet: popup-based add page, favicon auto-detect
- Multi-tab sync: BroadcastChannel for theme + data changes
- i18n translations for all new strings (EN/RU)

src/routes/admin/settings/+page.server.ts

@@ -34,7 +34,14 @@ export const load: PageServerLoad = async (event) => {
 		zod(updateSystemSettingsSchema)
 	);
 
-	return { settings, form };
+	return {
+		settings,
+		form,
+		discoveryConfig: {
+			dockerSocketPath: process.env.DOCKER_SOCKET_PATH || '/var/run/docker.sock',
+			traefikApiUrl: process.env.TRAEFIK_API_URL || ''
+		}
+	};
 };
 
 export const actions: Actions = {

src/routes/admin/settings/+page.svelte

@@ -3,8 +3,12 @@
 	import type { PageData } from './$types.js';
 	import SettingsForm from '$lib/components/admin/SettingsForm.svelte';
 	import ImportExportPanel from '$lib/components/admin/ImportExportPanel.svelte';
+	import DiscoveryPanel from '$lib/components/admin/DiscoveryPanel.svelte';
 
 	let { data }: { data: PageData } = $props();
+
+	let dockerSocketPath = $state(data.discoveryConfig?.dockerSocketPath ?? '/var/run/docker.sock');
+	let traefikApiUrl = $state(data.discoveryConfig?.traefikApiUrl ?? '');
 </script>
 
 <svelte:head>
@@ -17,7 +21,9 @@
 		<p class="mt-1 text-sm text-muted-foreground">{$t('admin.settings_description')}</p>
 	</div>
 
-	<SettingsForm form={data.form} />
+	<SettingsForm form={data.form} bind:dockerSocketPath bind:traefikApiUrl />
+
+	<DiscoveryPanel bind:dockerSocketPath bind:traefikApiUrl />
 
 	<ImportExportPanel />
 </div>