Revert: don't set default terminal in setup.sh

Setting default terminal is a user preference, done manually.

setup.sh

@@ -23,9 +23,6 @@ echo ">>> Installing bash, kitty, and vim..."
 sudo apt update
 sudo apt install -y bash kitty vim-gtk3 git curl
 
-echo ">>> Setting kitty as default terminal..."
-sudo update-alternatives --install /usr/bin/x-terminal-emulator x-terminal-emulator /usr/bin/kitty 20
-
 # 2. Clone your dotfiles (bare repo style)
 if [ ! -d "$HOME/.dotfiles" ]; then
     echo ">>> Cloning dotfiles repo..."