Ship out-of-the-box VSCode-style config and sharp rendering defaults

- quilt patch: first-run user init.lua template now writes a tuned
  default config (Dark Modern theme, JetBrains Mono with grayscale AA,
  line-height/indent guides, compact treeview with hover highlight)
- new theme module usr/share/lite-xl/colors/vscode_dark.lua
- default config in /etc/skel/.config/lite-xl/ for new users
- desktop: launch via SDL software renderer with LITE_SCALE=1.5 so text
  renders 1:1 on fractional-scaled Wayland outputs and avoids panfrost
  GPU artifacts
- depend on fonts-jetbrains-mono for the default code font

debian/control

@@ -15,7 +15,7 @@ Homepage: https://lite-xl.com/
 
 Package: lite-xl
 Architecture: any
-Depends: ${shlibs:Depends}, ${misc:Depends}
+Depends: ${shlibs:Depends}, ${misc:Depends}, fonts-jetbrains-mono
 Description: A lightweight text editor written in Lua
  A lightweight, fast and extensible text editor written in Lua, designed to be
  highly customizable and to have a small footprint. It is written in C and Lua