YouTube: Maintainability issues

### Is there an existing issue outlining your problem?

- [x] I have searched the existing issues and they do not solve my problem.

### What userstyle are you seeing the problem on?

lbl:youtube

### Describe your problem.

As mentioned at https://github.com/catppuccin/userstyles/issues/2219#issuecomment-4269138949, YouTube as it migrates towards a styling solution matching modern Google Search is become almost impossible to maintain.

This is a subsection of some of the new hashed CSS variables.

```css
[dark] {
--t7f4f2c6d54836ce0: rgba(255,255,255,0.1);
--t7d8b8e5ee291aec0: rgba(0,0,0,0.05);
--t4726c68ef6d7b08f: rgba(0,63,13,0.6);
--tf0a0d1154827847f: rgba(124,41,0,0.6);
...
```

```css
.ytChipShapeActive {
background-color: var(--t1405e70a39276293);
color: var(--t6216186c28b3834b);
}
```

```css
html:not(.style-scope) {
--paper-dialog-background-color: var(--t518e925f61bdcb91);
--paper-listbox-background-color: var(--t518e925f61bdcb91);
--paper-listbox-color: var(--tffc2fd3a644f6275);
}
```

While these updates also introduced new YouTube system variables (`--yt-spec-*`), the hardcoded variables are not being bound to these and instead are being resolved at SCSS build time.

It should be determined how we should move forward from this.

Related: #2219, #2217, #2212

### Attach screenshots.

_No response_

### Browser version(s) this issue occurs on

N/A

### Stylus extension version

N/A

### Installed version of the userstyle

N/A

### Any additional comments?

_No response_

Start by reading the related issues and discussion in #2219, #2217, and #2212, then compare the hashed variables, --yt-spec-* variables, and SCSS build-time resolution described here. The issue is complete when the project has an agreed, documented direction for making the YouTube userstyle maintainable; no target files or tests are named.

Written by the indexing model from the issue text.