Supplement telemetry rosters with fresh RCON pings

tests/unit/host-status-batch.test.ts

@@ -1,5 +1,6 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import { newFixture, type Fixture } from '../helpers/fixture.js';
+import { gameEvent, postTelemetry } from '../helpers/telemetry.js';
 
 let fixture: Fixture;
 let at: number;
@@ -45,6 +46,19 @@ async function setup(count = 5, hostCount = 1) {
 }
 
 describe('host status observations', () => {
+    it('batches occupied telemetry lobbies for pings while skipping empty lobbies', async () => {
+        const api = await setup(2);
+        await postTelemetry(gameEvent('heartbeat', 15, 1, 'server-0-0'));
+        await postTelemetry(gameEvent('heartbeat', 15, 0, 'server-0-1'));
+        const pass = api.fanoutStatus();
+        try {
+            await vi.waitFor(() => expect(api.operations()).toHaveLength(1));
+            expect(api.operations()[0]).toMatchObject({ kind: 'rcon.status-batch',
+                payload: { instances: [{ instanceId: 'instance-0-0', generation: 1 }] } });
+        } finally { api.complete(); await pass; }
+        expect(api.getServer('server-0-1')?.last_seen_at).toBeNull();
+    });
+
     it('bounds monitoring reads below five per server across thirty instances', async () => {
         const api = await setup(10, 3);
         const hosts = await import('../../src/lib/server/hosts/index.js');