Add multi-server blueprint collections and atomic launches

src/routes/api/deployment-collections/preview/+server.ts

@@ -0,0 +1,9 @@
+import { json } from '@sveltejs/kit';
+import { previewCollection } from '$lib/server/fleet/collections.js';
+
+export async function POST({ request }: { request: Request }) {
+    try {
+        const body = await request.json();
+        return json(previewCollection(body?.blueprintId));
+    } catch (err) { return json({ error: (err as Error).message }, { status: 400 }); }
+}