Add migration for easier tmux pane controls

Updates existing users' terminal and tmux configs to match ca19e2de:
Alt+Enter/Alt+Shift+Enter splits and Alt+Escape kill in tmux, plus
CSI-u Shift+Enter encodings across alacritty, foot, ghostty, and kitty.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

migrations/1783833508.sh

@@ -0,0 +1,46 @@
+echo "Add easier tmux pane controls with Alt+Enter splits and CSI-u Shift+Enter across terminals"
+
+# tmux: add M-Enter/M-S-Enter/M-Escape pane bindings and enable extkeys for kitty terminal
+tmux_config="$HOME/.config/tmux/tmux.conf"
+if [[ -f $tmux_config ]]; then
+  if ! grep -q "M-S-Enter" "$tmux_config"; then
+    sed -i '/^# Pane Controls$/a\bind -n M-Enter split-window -v -c "#{pane_current_path}"\nbind -n M-S-Enter split-window -h -c "#{pane_current_path}"\nbind -n M-Escape kill-pane\n' "$tmux_config"
+  fi
+
+  if ! grep -q "terminal-features" "$tmux_config"; then
+    sed -i '/^set -g extended-keys-format csi-u$/a\set -g terminal-features[3] "xterm-kitty:extkeys"' "$tmux_config"
+  fi
+
+  omarchy-restart-tmux
+fi
+
+# alacritty: replace the old Shift+Return binding with CSI-u encodings
+alacritty_config="$HOME/.config/alacritty/alacritty.toml"
+if [[ -f $alacritty_config ]] && ! grep -q '13;2u' "$alacritty_config"; then
+  sed -i -E 's|^([[:space:]]*).*chars = "\\u001B\\r".*|\1# Send Shift+Return as CSI-u so TUIs can distinguish it from Return without treating it as Alt+Return.\n\1{ key = "Return", mods = "Shift", chars = "\\u001B[13;2u" },\n\1# Legacy encoding sends Alt+Shift+Return the same as Alt+Return; send CSI-u so tmux can match M-S-Enter.\n\1{ key = "Return", mods = "Alt\|Shift", chars = "\\u001B[13;4u" }|' "$alacritty_config"
+fi
+
+# foot: append CSI-u text bindings for Shift+Return and Alt+Shift+Return
+foot_config="$HOME/.config/foot/foot.ini"
+if [[ -f $foot_config ]] && ! grep -q '13;2u' "$foot_config"; then
+  cat >>"$foot_config" <<'EOF'
+
+[text-bindings]
+# Send Shift+Return as CSI-u so TUIs can distinguish it from Return.
+\x1b[13;2u=Shift+Return
+# Send Alt+Shift+Return as CSI-u so tmux can match M-S-Enter.
+\x1b[13;4u=Mod1+Shift+Return
+EOF
+fi
+
+# ghostty: add CSI-u keybinds for Shift+Enter and Alt+Shift+Enter
+ghostty_config="$HOME/.config/ghostty/config"
+if [[ -f $ghostty_config ]] && ! grep -q 'csi:13;2u' "$ghostty_config"; then
+  sed -i '/^keybind = control+insert=copy_to_clipboard$/a\# Send Shift+Enter as CSI-u so TUIs can distinguish it from Enter.\nkeybind = shift+enter=csi:13;2u\n# Legacy encoding sends Alt+Shift+Enter the same as Alt+Enter; send CSI-u so tmux can match M-S-Enter.\nkeybind = alt+shift+enter=csi:13;4u' "$ghostty_config"
+fi
+
+# kitty: add CSI-u key mappings for Shift+Enter and Alt+Shift+Enter
+kitty_config="$HOME/.config/kitty/kitty.conf"
+if [[ -f $kitty_config ]] && ! grep -q '13;2u' "$kitty_config"; then
+  sed -i '/^map shift+insert paste_from_clipboard$/a\# Send Shift+Enter as CSI-u so TUIs can distinguish it from Enter.\nmap shift+enter send_text all \\e[13;2u\n# Kitty legacy encoding sends Alt+Shift+Enter the same as Alt+Enter; send CSI-u so tmux can match M-S-Enter.\nmap alt+shift+enter send_text all \\e[13;4u' "$kitty_config"
+fi