feat(cli): port ghostty +action CLI commands

Ports ZIG/src/cli into ghostty-cli: action detection/dispatch with
per-action --help, and the actions help, version, list-actions,
list-colors, list-keybinds, list-themes (plain listing plus an
interactive ratatui browser mirroring Ghostty's libvaxis UI),
show-config, validate-config, edit-config, crash-report (listing),
ssh-cache and boo (235 embedded frames).

Verified byte-for-byte against the installed Ghostty 1.3.1 for stdout,
stderr and exit codes of most actions, incl. tty output in a pty at
widths 20-200. Known differences: +list-colors --plain prints all 782
colors (Ghostty truncates at 617 because it never flushes), +version
has placeholder build info until build_info::set is wired up.

Deferred: list-fonts, show-face (need font discovery integration) and
new-window (needs GTK IPC); they return NotYetAvailable for now.

Test Plan:
- cargo test -p ghostty-cli (86 tests)
- cargo run -p ghostty-cli --example cli -- +list-keybinds --plain
  and diff against `ghostty +list-keybinds --plain`

crates/ghostty-cli/src/list_actions.rs

@@ -0,0 +1,108 @@
+//! `+list-actions` (ZIG/src/cli/list_actions.zig).
+
+use std::io::Write;
+
+use ghostty_config::config_struct;
+use ghostty_input::binding::ActionKey;
+
+use crate::error::Error;
+
+config_struct! {
+    pub struct Options {
+        /// If `true`, print out documentation about the action associated with the
+        /// keybinds.
+        "docs" => docs: bool = false,
+    }
+}
+cli_options!(Options, help);
+
+/// The `list-actions` command is used to list all the available keybind
+/// actions for Ghostty. These are distinct from the CLI Actions which can
+/// be listed via `+help`
+///
+/// Flags:
+///
+///   * `--docs`: will print out the documentation for each action.
+pub fn run(args: &[String]) -> Result<u8, Error> {
+    let mut opts = Options::default();
+    crate::parse_options(&mut opts, args)?;
+
+    let out = generate_plaintext(opts.docs);
+    let mut stdout = std::io::stdout().lock();
+    stdout.write_all(out.as_bytes())?;
+    stdout.flush()?;
+    Ok(0)
+}
+
+/// `helpgen_actions.generate(.plaintext, show_docs)`.
+///
+/// TODO(integration): this is a local copy of
+/// `ghostty_input::helpgen_actions::generate`. The embedded docs of a few
+/// actions in ghostty-input (`adjust_selection`, ...) end with an extra blank
+/// line compared to Ghostty's `help_strings`, which adds a stray `"  "` line
+/// to `--docs` output. Trailing newlines are normalised here; once the data
+/// is fixed in ghostty-input this should call `helpgen_actions::generate`.
+#[must_use]
+pub fn generate_plaintext(show_docs: bool) -> String {
+    let mut writer = String::new();
+    let mut stream = String::new();
+    for &key in ActionKey::ALL {
+        let name = key.name();
+        if name.starts_with('_') {
+            continue;
+        }
+
+        // Write previously stored doc comment below all related actions
+        if show_docs {
+            writer.push_str(&stream);
+            writer.push('\n');
+            stream.clear();
+            writer.push_str(name);
+            writer.push_str(":\n");
+            for line in key.docs().trim_end_matches('\n').split('\n') {
+                stream.push_str("  ");
+                stream.push_str(line);
+                stream.push('\n');
+            }
+        } else {
+            writer.push_str(name);
+            writer.push('\n');
+        }
+    }
+
+    // Write any remaining buffered documentation
+    writer.push_str(&stream);
+    writer
+}
+
+#[cfg(test)]
+mod tests {
+    #![allow(clippy::unwrap_used)]
+    use super::*;
+
+    #[test]
+    fn names_only() {
+        let s = generate_plaintext(false);
+        assert!(s.starts_with("ignore\nunbind\ncsi\n"));
+        assert!(!s.contains(':'));
+    }
+
+    #[test]
+    fn docs_have_no_stray_blank_lines_between_actions() {
+        let s = generate_plaintext(true);
+        assert!(s.starts_with("\nignore:\n  Ignore this key combination.\n"));
+        assert!(s.contains("      respectively.\n\njump_to_prompt:\n"));
+        assert!(s.ends_with('\n'));
+    }
+
+    #[test]
+    fn matches_input_crate_when_docs_are_clean() {
+        // The first actions have well-formed docs.
+        let ours = generate_plaintext(true);
+        let theirs = ghostty_input::helpgen_actions::generate_string(
+            ghostty_input::helpgen_actions::Format::Plaintext,
+            true,
+        );
+        assert!(ours.lines().take(100).eq(theirs.lines().take(100)));
+    }
+}