Backport: Css token standardization (#6363) (#6669)

## Summary
Backports the CSS token standardization changes from PR #6363 to the
`core/1.30` branch.

Resolved merge conflict in `MediaTitle.vue` and added missing
`truncateFilename` function to maintain compatibility.

**Original PR**: https://github.com/Comfy-Org/ComfyUI_frontend/pull/6363
**Cherry-picked commit**: bde5244a71

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6669-Backport-Css-token-standardization-6363-2aa6d73d36508153be09cdc67f6ac8a4)
by [Unito](https://www.unito.io)

src/components/graph/selectionToolbox/BypassButton.vue

@@ -7,7 +7,7 @@
     severity="secondary"
     text
     data-testid="bypass-button"
-    class="hover:bg-[#E7E6E6] hover:dark-theme:bg-charcoal-600"
+    class="hover:bg-secondary-background"
     @click="toggleBypass"
   >
     <template #icon>