Chrome window indicator not showing despite correct app-id matching

### What Happened?

The dock does not show running window indicators (dots) under the Google Chrome launcher, even when Chrome windows are open. Other applications (Karere, Bitwarden, Ghostty) show indicators correctly.

### Diagnostic Information

Gala correctly identifies Chrome windows via D-Bus:
```
gdbus call --session --dest io.elementary.gala --object-path /org/pantheon/gala/DesktopInterface --method org.pantheon.gala.DesktopIntegration.GetWindows
```

Returns:
```
'app-id': <'google-chrome.desktop'>,
'wm-class': <'Google-chrome'>
```

Gala also correctly reports Chrome in running applications:
```
gdbus call --session --dest io.elementary.gala --object-path /org/pantheon/gala/DesktopInterface --method org.pantheon.gala.DesktopIntegration.GetRunningApplications
```

Returns `google-chrome.desktop` in the list.

The dock launcher is configured with `google-chrome.desktop`:
```
gsettings get io.elementary.dock launchers
```

GLib correctly finds the desktop file:
```python
from gi.repository import Gio
app_info = Gio.DesktopAppInfo.new('google-chrome.desktop')
print(app_info.get_filename()) # Returns correct path
```

### Steps to Reproduce

1. Pin Google Chrome to the dock
2. Open a Chrome window
3. Observe: no indicator dot appears under the Chrome launcher
4. Compare with other apps (e.g., Files, Bitwarden) which show indicators

### Expected Behavior

The dock should show an indicator dot under the Chrome launcher when Chrome windows are open, matching the behavior of other applications.

### Intermittent Behavior

The indicator has appeared intermittently (e.g., after opening a second window), suggesting a race condition or timing issue in window-to-launcher association.

### Environment

- OS Version: elementary OS 8 (Circe)
- Session Type: Wayland
- Chrome: Native deb package (not Flatpak)
- Dock version: 8.3.1

### Notes

- The system desktop file (`/usr/share/applications/google-chrome.desktop`) has no `StartupWMClass` entry
- Adding `StartupWMClass=google-chrome` or `StartupWMClass=Google-chrome` to an override file does not fix the issue
- Other native apps with similar WM_CLASS patterns work correctly