The WebKit HTML preview previously rendered fenced code blocks
monochrome. Wire the existing tokenizer into the HTML renderer so code
blocks are highlighted like GitHub, and extend language coverage.
- markdown.c: accumulate each code block's text, tokenize it on block
leave, and emit <span class="pl-*"> per token with HTML-escaped gaps
and token text; unknown languages fall back to plain escaped text.
- Add GitHub Primer syntax colors (light/dark) for keywords, constants,
strings, and comments.
- code_highlight.c: tokenize comments (//, /* */, #), which were
previously skipped and left uncolored.
- Add languages: javascript, kotlin, and bash (aliases js, kt, sh,
shell). Bash uses a dedicated scanner whose '#' comments are
word-position aware so $#, x=$#, and a.com#frag are not comments.
- Create the code_comment tag so the source editor colors comments too.
- README: document the highlighted languages.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>