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/api/admin/discover/approve/+server.ts

@@ -0,0 +1,70 @@
+import { json } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+import { requireAdmin } from '$lib/server/middleware/authorize.js';
+import { create } from '$lib/server/services/appService.js';
+import { success, error } from '$lib/server/utils/response.js';
+
+interface ApproveServiceInput {
+	readonly name: string;
+	readonly url: string;
+	readonly source: 'docker' | 'traefik';
+	readonly icon?: string;
+	readonly description?: string;
+}
+
+interface ApproveBody {
+	readonly services: readonly ApproveServiceInput[];
+}
+
+/**
+ * POST /api/admin/discover/approve — Approve discovered services and create app entries. Admin only.
+ *
+ * Body: { services: DiscoveredService[] }
+ */
+export const POST: RequestHandler = async (event) => {
+	const user = requireAdmin(event);
+
+	let body: ApproveBody;
+	try {
+		body = await event.request.json();
+	} catch {
+		return json(error('Invalid JSON body'), { status: 400 });
+	}
+
+	if (!body.services || !Array.isArray(body.services) || body.services.length === 0) {
+		return json(error('At least one service must be provided for approval'), { status: 400 });
+	}
+
+	const created: string[] = [];
+	const errors: string[] = [];
+
+	for (const service of body.services) {
+		if (!service.name || !service.url) {
+			errors.push(`Skipped invalid service entry (missing name or url)`);
+			continue;
+		}
+
+		try {
+			const app = await create({
+				name: service.name,
+				url: service.url,
+				icon: service.icon,
+				description: service.description ?? `Discovered via ${service.source}`,
+				category: 'Discovered',
+				healthcheckEnabled: true,
+				createdById: user.id
+			});
+			created.push(app.id);
+		} catch (err) {
+			const message = err instanceof Error ? err.message : 'Unknown error';
+			errors.push(`Failed to create "${service.name}": ${message}`);
+		}
+	}
+
+	return json(
+		success({
+			created: created.length,
+			errors
+		})
+	);
+};