feat(companion): add manual heartbeat tick helper

src/companion/heartbeatLoop.test.ts

@@ -130,4 +130,14 @@ describe('CompanionHeartbeatLoop', () => {
     await vi.advanceTimersByTimeAsync(1000);
     expect(publishHeartbeat).toHaveBeenCalledTimes(2);
   });
+
+  it('tickNow sends heartbeat even when loop is not started', async () => {
+    const publishHeartbeat = vi.fn(async () => buildStatusResult());
+    const loop = new CompanionHeartbeatLoop({ publishHeartbeat }, { intervalMs: 1000 });
+
+    expect(loop.running).toBe(false);
+    await loop.tickNow();
+    expect(publishHeartbeat).toHaveBeenCalledTimes(1);
+    expect(loop.running).toBe(false);
+  });
 });