2026-08-18 — Appearance font preview + install

  • settings_dialog.d: editable preview pane wearing the selected mono; install status warning when the OS lacks the face.

  • font_install.d: spawn scriptbook run examples/fonts/install-*.cmk --catalog equivalence-rules-cli/catalog/tools.sdl when scriptbook is on PATH (platform --format: choco / brew / nix).

  • fonts.d: isCodeFontInstalled, applyPreviewCodeFont, default pangram + D sample from font-lock spec.

  • Ligature toggle deferred; Cascadia Mono stays the no-ligature default by family name. Shipped in follow-up: 2026-08-18 appearance-font-deferred.