yazi: palette doc image + regeneration script for kanagawa-dragon

[kriswill]

What

Documents the kanagawa-dragon yazi theme's colors in a single rendered image, plus a script that regenerates it from the theme's own source files (so it can't drift).

Changes

• scripts/render-yazi-palette.ts — a bun script that:
  • parses flavor.toml (color names from the ## Color palette comment block, plus a usage scan showing where each hex is referenced, e.g. mgr.cwd, status.perm_read);
  • parses tmtheme.xml via a minimal plist parser (handles the self-closing <string/> tags used for empty fontStyles);
  • renders a labeled swatch grid via ImageMagick and overwrites palette.png.
  • Re-run anytime: bun scripts/render-yazi-palette.ts. Font is discovered from the Nix store (overridable via FONT_REGULAR/FONT_BOLD); deps are bun + ImageMagick.
• _themes/kanagawa-dragon/palette.png — the generated documentation image: UI theme (18 colors), tmtheme editor globals (6), and syntax scopes (21 unique colors), each labeled with name / hex / usage.

Notes

• Fully data-driven — names and usage come from the files themselves, so the image stays correct as the theme changes.
• Surfaced one gap: #8ea4a2 (used for all borders) is not named in flavor.toml's palette comment block; the script labels it dragonAqua via a small alias map.
• Independent of yazi: wire lua_ls type checking for font-dark previewer #9 (LSP types) — touches only the script and the image.

Verification

bun scripts/render-yazi-palette.ts → wrote .../palette.png (1760x2382) · flavor: 18, tmtheme editor: 6, scopes: 21.