Vendor highlight.js (core + python, javascript, typescript, json, yaml,
bash) and highlight the file viewer's text kind (computed once per load)
plus fenced blocks in renderMarkdown. Colors come from new --syn-* CSS
variables aliased to the existing palette, so dark mode follows.
get_ast_outline was the one registry tool with no Tool::display_name and no
Tool::icon, so its chat card fell back to the raw function id and the generic
Filesystem glyph. It now declares "Code Outline" plus a new semantic icon key
'outline', mapped frontend-side to bi-list-nested with its own accent var in
both themes.
Daniele
dguiducci