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/show_face.rs

@@ -0,0 +1,78 @@
+//! `+show-face` (ZIG/src/cli/show_face.zig).
+//!
+//! DEFERRED: needs the font crate (collection / codepoint resolver). Only the
+//! options and help are ported; running the action reports that it is not
+//! available.
+
+use ghostty_config::{config_enum, config_struct, diagnostics::DiagnosticList};
+
+use crate::error::Error;
+
+config_enum! {
+    /// Font style (Zig: `font.Style`).
+    pub enum Style {
+        Regular => "regular",
+        Bold => "bold",
+        Italic => "italic",
+        BoldItalic => "bold_italic",
+    }
+}
+
+config_enum! {
+    /// Font presentation (Zig: `font.Presentation`).
+    pub enum Presentation {
+        Text => "text",
+        Emoji => "emoji",
+    }
+}
+
+config_struct! {
+    pub struct Options {
+        /// The codepoint to search for.
+        "cp" => cp: Option<u32> = None,
+
+        /// Search for all of the codepoints in the string.
+        "string" => string: Option<String> = None,
+
+        /// Font style to search for.
+        "style" => style: Style = Style::Regular,
+
+        /// If specified, force text or emoji presentation.
+        "presentation" => presentation: Option<Presentation> = None,
+    }
+    extra {
+        // Enable arg parsing diagnostics so that we don't get an error if
+        // there is a "normal" config setting on the cli.
+        diagnostics: DiagnosticList = DiagnosticList::default(),
+    }
+}
+cli_options!(Options, help, diagnostics);
+
+/// The `show-face` command shows what font face Ghostty will use to render a
+/// specific codepoint. Note that this command does not take into consideration
+/// grapheme clustering or any other Unicode features that might modify the
+/// presentation of a codepoint, so this may show a different font face than
+/// Ghostty uses to render a codepoint in a terminal session.
+///
+/// Flags:
+///
+///   * `--cp`: Find the face for a single codepoint. The codepoint may be specified
+///     in decimal (`--cp=65`), hexadecimal (`--cp=0x41`), octal (`--cp=0o101`), or
+///     binary (`--cp=0b1000001`).
+///
+///   * `--string`: Find the face for all of the codepoints in a string. The
+///     string must be a valid UTF-8 sequence.
+///
+///   * `--style`: Search for a specific style. Valid options are `regular`, `bold`,
+///     `italic`, and `bold_italic`.
+///
+///   * `--presentation`: If set, force searching for a specific presentation
+///     style. Valid options are `text` and `emoji`. If unset, the presentation
+///     style of a codepoint will be inferred from the Unicode standard.
+pub fn run(args: &[String]) -> Result<u8, Error> {
+    let mut opts = Options::default();
+    crate::parse_options(&mut opts, args)?;
+
+    // TODO(integration): port the face lookup once ghostty-font lands.
+    Err(Error::NotYetAvailable("show-face"))
+}