[backport v2.14.5] Extension changes colour of kube describe icon in header

[rancher-ui-project-bot]

This is a backport issue for #18278, automatically created via GitHub Actions workflow initiated by @torchiaf

Original issue body:

Describe the bug

• After installing the AI extension the header bar icon for 'Kube Describe' turns black rather than the theme/brand text colour
• shell/components/IconOrSvg.vue --> css fn in shell/utils/svg-filter.js should apply custom styling but it's not

To Reproduce

• Install the ai extension (i tested with an ancient
• nav to rancher ui home page
• refresh
• local cluster --> cluster --> node

Result

• the header bar's kube describe svg is black

Expected Result

• the header bar's kube describe svg is the appropriate colour given the theme/brand

Screenshots

Additional context

• this affects both light and dark modes
• this is not reproducible if refreshing directly on the page
• There might still be a chance this a general bug up upstream r/d, however i did test using a range of old to fresh versions of the harvester extension and could not reproduce (1.06, 1.61, 1.81)
• thought it might be related to this, but that's the side bar