Media resources specified in expanding commands are not evaluated properly, resulting in errors

@DHowett is already working on this.

Since Mar 11, 2026.

### Windows Terminal version

1.24.10621.0

### Windows build number

10.0.26100.0

### Other Software

_No response_

### Steps to reproduce

Launch Terminal with a backgroundImage specified in `settings.json`.

Example configuration:
```json
{
"$help": "https://aka.ms/terminal-documentation",
"$schema": "https://aka.ms/terminal-profiles-schema",
"actions": [],
"defaultProfile": "{574e775e-4f2a-5b96-ac1e-a2962a402336}",
"keybindings": [],
"launchMode": "maximizedFocus",
"newTabMenu": [
{
"type": "remainingProfiles"
}
],
"profiles": {
"defaults": {
"colorScheme": "Ayu Mirage",
"cursorShape": "filledBox",
"elevate": true,
"font": {
"face": "JetBrainsMono Nerd Font",
"size": 10
},
"opacity": 0,
"padding": "0",
"scrollbarState": "hidden",
"useAcrylic": true,
"backgroundImage": "%USERPROFILE%/.dotfiles/windows-terminal/background.png"
},
"list": [
{
"guid": "{574e775e-4f2a-5b96-ac1e-a2962a402336}",
"hidden": false,
"name": "PowerShell",
"source": "Windows.Terminal.PowershellCore"
}
]
},
"schemes": [
{
"background": "#1F2430",
"black": "#191E2A",
"blue": "#6DCBFA",
"brightBlack": "#686868",
"brightBlue": "#73D0FF",
"brightCyan": "#95E6CB",
"brightGreen": "#BAE67E",
"brightPurple": "#D4BFFF",
"brightRed": "#F28779",
"brightWhite": "#FFFFFF",
"brightYellow": "#FFD580",
"cursorColor": "#FFFFFF",
"cyan": "#90E1C6",
"foreground": "#CBCCC6",
"green": "#A6CC70",
"name": "Ayu Mirage",
"purple": "#FF4BFF",
"red": "#ED8274",
"selectionBackground": "#FFFFFF",
"white": "#C7C7C7",
"yellow": "#FAD07B"
}
],
"themes": []
}
```

### Expected Behavior

Profile loads without showing the error. Was no issue in prior versions. I also tried to regenerate `settings.json` as well as clearing `LocalCache`. Using explicit path as well as URI-Schemes or placing the image directly in `LocalState` is not working either. Manually configuring image path using Settings UI is also not working.

Funny enough, `backgroundImage` is loading and displayed as expected.

### Actual Behavior