Wrong resolution sent to `spice-vdagent` for external monitor when waking from sleep.

**Describe the issue**
macOS host, linux guest.

My macbook is hooked up to an external monitor and I have the guest running full-screen in that monitor. When the host laptop sleeps, and then is woken from sleep, a message is sent to the guest's spice-vdagent informing it that the monitor's resolution is 1920x1080, which is wrong, since my monitor is in fact 3840x2160.

To prove this, I am running `spice-vdagent` in the guest with this patch applied:

```diff
diff -ur spice-vdagent-0.22.1-pristine/src/vdagent/x11-randr.c spice-vdagent-0.22.1/src/vdagent/x11-randr.c
--- spice-vdagent-0.22.1-pristine/src/vdagent/x11-randr.c 2025-11-18 13:51:00.450511896 -0700
+++ spice-vdagent-0.22.1/src/vdagent/x11-randr.c 2025-11-18 14:00:10.050468579 -0700
@@ -841,6 +841,12 @@
VDAgentMonitorsConfig *mon_config,
int fallback)
{
+ syslog(LOG_INFO, "[btv] vdagent_x11_set_monitor_config: %d", mon_config->num_of_monitors);
+ for (int i = 0; i < mon_config->num_of_monitors; ++i) {
+ VDAgentMonConfig *m = &mon_config->monitors[i];
+ syslog(LOG_INFO, "[btv] %d: %d/%d/%d (%d/%d)", i, m->width,
+ m->height, m->depth, m->x, m->y);
+ }
int primary_w, primary_h;
int i, real_num_of_monitors = 0;
VDAgentMonitorsConfig *curr = NULL;
```

It is causing messages like this to be printed to the syslog:

```
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] vdagent_x11_set_monitor_config: 16
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 0: 1920/1080/32 (0/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 1: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 2: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 3: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 4: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 5: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 6: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 7: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 8: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 9: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 10: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 11: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 12: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 13: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 14: 0/0/0 (1920/0)
2025-11-19 09:21:17 localhost spice-vdagent[986]: [btv] 15: 0/0/0 (1920/0)
```

I'm not sure why it thinks I have 16 monitors, but anyway, that's a separate question. The point is that the wrong resolution is being reported for monitor 0.

**Configuration**
* UTM Version: 4.7.4
* macOS Version: Sequoia 15.6
* Mac Chip (Intel, M1, ...): Apple M3 Max

**Debug log**
For all issues related to running a VM, _including_ crashes, you should attach a debug log. (This is unavailable for macOS-on-macOS VMs. Attach an excerpt of your system log instead.)
To get the Debug log: open UTM, and open the settings for the VM you wish to launch. Near the top of the `QEMU` page is `Debug Log`. Turn it on and save the VM. After you experience the issue, open the VM settings again and select `Export Log...` and attach it here.

[debug.log](https://github.com/user-attachments/files/23633314/debug.log)