shell-integration: implement "no-cursor" option

Implement a "no-cursor" option for shell integration. This option acts
like "detect" but doesn't set the cursor shape.

src/config/Config.zig

@@ -532,6 +532,8 @@ keybind: Keybinds = .{},
 ///     configure your shell to enable the integration.
 ///   * "detect" - Detect the shell based on the filename.
 ///   * "fish", "zsh" - Use this specific shell injection scheme.
+///   * "no-cursor" - Detect the shell as in 'detect', but doesn't set cursor
+///     shapes
 ///
 /// The default value is "detect".
 @"shell-integration": ShellIntegration = .detect,
@@ -2182,6 +2184,7 @@ pub const ShellIntegration = enum {
     detect,
     fish,
     zsh,
+    @"no-cursor",
 };
 
 /// OSC 10 and 11 default color reporting format.

src/shell-integration/bash/ghostty.bash

@@ -41,8 +41,10 @@ function __ghostty_precmd() {
       PS2=$PS2'\[\e]133;B\a\]'
 
       # Cursor
+    if test "$GHOSTTY_SHELL_INTEGRATION_NO_CURSOR" != "1"; then
       PS1=$PS1'\[\e[5 q\]'
       PS0=$PS0'\[\e[0 q\]'
+    fi
 
       # Command
       PS0=$PS0'$(__ghostty_get_current_command)'

src/shell-integration/fish/vendor_conf.d/ghostty-shell-integration.fish

@@ -51,6 +51,10 @@ status --is-interactive || ghostty_exit
 function __ghostty_setup --on-event fish_prompt -d "Setup ghostty integration"
     functions -e __ghostty_setup
 
+    # Check if we are setting cursors
+    set --local no_cursor "$GHOSTTY_SHELL_INTEGRATION_NO_CURSOR"
+
+    if test -z $no_cursor
         # Change the cursor to a beam on prompt.
         function __ghostty_set_cursor_beam --on-event fish_prompt -d "Set cursor shape"
             echo -en "\e[5 q"
@@ -58,6 +62,7 @@ function __ghostty_setup --on-event fish_prompt -d "Setup ghostty integration"
         function __ghostty_reset_cursor --on-event fish_preexec -d "Reset cursor shape"
             echo -en "\e[0 q"
         end
+    end
 
     # Setup prompt marking
     function __ghostty_mark_prompt_start --on-event fish_prompt --on-event fish_cancel --on-event fish_posterror
@@ -93,7 +98,9 @@ function __ghostty_setup --on-event fish_prompt -d "Setup ghostty integration"
     set --global fish_handle_reflow 1
 
     # Initial calls for first prompt
+    if test -z $no_cursor
         __ghostty_set_cursor_beam
+    end
     __ghostty_mark_prompt_start
     __update_cwd_osc
 end

src/shell-integration/zsh/ghostty-integration

@@ -200,6 +200,7 @@ _ghostty_deferred_init() {
     functions[_ghostty_preexec]+="
         builtin print -rnu $_ghostty_fd \$'\\e]2;'\"\${(V)1}\"\$'\\a'"
 
+    if [[ "$GHOSTTY_SHELL_INTEGRATION_NO_CURSOR" != 1 ]]; then
       # Enable cursor shape changes depending on the current keymap.
       # This implementation leaks blinking block cursor into external commands
       # executed from zle. For example, users of fzf-based widgets may find
@@ -215,6 +216,7 @@ _ghostty_deferred_init() {
       # Restore the blinking default shape before executing an external command
       functions[_ghostty_preexec]+="
 	  builtin print -rnu $_ghostty_fd \$'\\e[0 q'"
+    fi
 
     # Some zsh users manually run `source ~/.zshrc` in order to apply rc file
     # changes to the current shell. This is a terrible practice that breaks many

src/termio/Exec.zig

@@ -812,6 +812,13 @@ const Subprocess = struct {
                 .detect => null,
                 .fish => .fish,
                 .zsh => .zsh,
+                .@"no-cursor" => nc: {
+                    // We add an environment variable for the shell integration
+                    // scripts to pick up to prevent setting cursor shapes.
+                    // Setting to "no_cursor" means we will detect the shell
+                    try env.put("GHOSTTY_SHELL_INTEGRATION_NO_CURSOR", "1");
+                    break :nc null;
+                },
             };
 
             const dir = opts.resources_dir orelse break :shell null;