Linux: Shortcuts to select text using the keyboard not working in Ghostty

[LinuxUserGD]

Note: Same issue for macOS: #3142

OS: Gentoo Linux amd64 (LLVM/musl libc)
DE: KDE Plasma 6.3.80 (Wayland session)
Keyboard layout: QUERTZ

~ $ ghostty --version
Ghostty 1.1.0

Version
  - version: 1.1.0
  - channel: stable
Build Config
  - Zig version: 0.13.0
  - build mode : builtin.OptimizeMode.ReleaseFast
  - app runtime: apprt.Runtime.gtk
  - font engine: font.main.Backend.fontconfig_freetype
  - renderer   : renderer.OpenGL
  - libxev     : main.Backend.io_uring
  - desktop env: other
  - GTK version:
    build      : 4.17.3
    runtime    : 4.17.3
  - libadwaita : enabled
    build      : 1.6.3
    runtime    : 1.6.3
  - libX11     : enabled
  - libwayland : enabled

Steps to reproduce:

• open Ghostty
• move the cursor while entering a command
• try to select text (shift+arrow keys)

Expected: https://testingkeyboard.com/10-word-shortcuts-to-select-text-using-a-keyboard/

[00-kat]

They're not bound by default, but you can find them with select_all and adjust_selection if you like. Do note that if you do this, terminal applications running inside Ghostty, such as Micro, would no longer be able to use those keys (although adding performable: may work; I've never tried it though).