On new version(1.6) fonts of icons are broken

### Compositor

Niri

### Distribution

Arch Linux

### If Other, please specify

_No response_

### Select your Installation Method

DankInstaller

### Was this your original Installation method?

Yes

### If no, specify

_No response_

### dms doctor -vC

none

### Description

After upgrading from 1.5.3 to 1.6.0, the app icons in the bar (task/window list)
changed appearance. In 1.5.3 they rendered as uniform dark rounded squares with a
colored glyph. In 1.6.0 they render as icons from the system icon theme instead.

I would like a way to get the 1.5.3 appearance back on 1.6.0.

### Expected Behavior

An option to keep the previous icon resolution behaviour, or a documented way to
force the built-in glyph rendering instead of icon-theme lookup.

### Steps to Reproduce

1. Run 1.5.3 with Settings -> Icon Theme = "System Default"
2. Open several terminal windows (kitty) and other apps
3. Upgrade to 1.6.0 and `dms restart`
4. Bar icons now look different

### Error Messages/Logs

_No response_

### Screenshots/Recordings

this font is no more AVIALIABLE

Reproduce the change by running the listed 1.5.3-to-1.6.0 upgrade path with Settings → Icon Theme set to “System Default,” then compare the task/window-list icons. Trace the icon resolution behavior from that setting and verify whether the previous built-in glyph rendering can be restored. Done means the old appearance is available through an option or a documented way to force it.

Written by the indexing model from the issue text.