Add .scrollbar-thin and .scrollbar-thin-edge utility classes in
globals.css and apply them to sidebar, file tree, git changes,
git log, session files, diff preview, and message thread panels.
Replace scattered inline webkit-scrollbar overrides with the
shared classes for consistent appearance and gutter behavior.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Import KaTeX CSS in layout.tsx to ensure math formulas display correctly
in both dev and production modes. Convert LaTeX-style `\[...\]` / `\(...\)`
delimiters to `$$...$$` / `$...$` since remark-math only supports dollar
sign delimiters, fixing formula rendering for agents like Codex.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
