Recognize Rex terminals and enable Kitty graphics for pets (#58270)

## What changed

- Detect Rex from `TERM_PROGRAM=rex` or `TERM=xterm-rex` and report its name in terminal diagnostics.
- Enable Kitty graphics for pets in Rex.
- Use the detected terminal identity for Rex's label-only web links, extending that behavior to detection through `TERM`.

## Testing

Add Rex detection coverage for both environment variables and include Rex in the web-link rendering and Kitty graphics support tests.

GitOrigin-RevId: b237e8a6b3af50a55080573dc1e0badc2c139b42

codex-rs/cli/src/doctor.rs

@@ -1892,6 +1892,7 @@ fn terminal_name(info: &TerminalInfo) -> &'static str {
     match info.name {
         TerminalName::AppleTerminal => "Apple Terminal",
         TerminalName::Ghostty => "Ghostty",
+        TerminalName::Rex => "Rex",
         TerminalName::Iterm2 => "iTerm2",
         TerminalName::WarpTerminal => "Warp",
         TerminalName::VsCode => "VS Code",

codex-rs/terminal-detection/src/lib.rs

@@ -40,6 +40,8 @@ pub enum TerminalName {
     AppleTerminal,
     /// Ghostty terminal emulator.
     Ghostty,
+    /// Rex terminal emulator.
+    Rex,
     /// iTerm2 terminal emulator.
     Iterm2,
     /// Warp terminal emulator.
@@ -138,6 +140,7 @@ impl TerminalInfo {
         let name = match term.as_str() {
             "dumb" => TerminalName::Dumb,
             "xterm-ghostty" => TerminalName::Ghostty,
+            "xterm-rex" => TerminalName::Rex,
             "wezterm" | "wezterm-mux" => TerminalName::WezTerm,
             _ => TerminalName::Unknown,
         };
@@ -176,6 +179,7 @@ impl TerminalInfo {
                     format_terminal_version("Apple_Terminal", &self.version)
                 }
                 TerminalName::Ghostty => format_terminal_version("Ghostty", &self.version),
+                TerminalName::Rex => format_terminal_version("rex", &self.version),
                 TerminalName::Iterm2 => format_terminal_version("iTerm.app", &self.version),
                 TerminalName::WarpTerminal => {
                     format_terminal_version("WarpTerminal", &self.version)
@@ -416,6 +420,7 @@ fn terminal_name_from_term_program(value: &str) -> Option<TerminalName> {
     match normalized.as_str() {
         "appleterminal" => Some(TerminalName::AppleTerminal),
         "ghostty" => Some(TerminalName::Ghostty),
+        "rex" => Some(TerminalName::Rex),
         "iterm" | "iterm2" | "itermapp" => Some(TerminalName::Iterm2),
         "warp" | "warpterminal" => Some(TerminalName::WarpTerminal),
         "vscode" => Some(TerminalName::VsCode),

codex-rs/terminal-detection/src/terminal_tests.rs

@@ -218,6 +218,14 @@ fn detects_ghostty() {
     );
 }
 
+#[test]
+fn detects_rex() {
+    for (key, value) in [("TERM_PROGRAM", "rex"), ("TERM", "xterm-rex")] {
+        let env = FakeEnvironment::new().with_var(key, value);
+        assert_eq!(detect_terminal_info_from_env(&env).name, TerminalName::Rex);
+    }
+}
+
 #[test]
 fn detects_vscode() {
     let env = FakeEnvironment::new()

codex-rs/tui/src/local_settings.rs

@@ -251,6 +251,7 @@ impl LocalSettings {
                         | TerminalName::Iterm2
                         | TerminalName::WarpTerminal
                         | TerminalName::WezTerm
+                        | TerminalName::Rex
                         | TerminalName::Alacritty
                         | TerminalName::Konsole
                         | TerminalName::GnomeTerminal

codex-rs/tui/src/markdown_render/web_links.rs

@@ -69,17 +69,11 @@ impl WebLinkDisplay {
         {
             return Self::WithDestination;
         }
-        if terminal
-            .term_program
-            .as_deref()
-            .is_some_and(|program| program.eq_ignore_ascii_case("rex"))
-        {
-            return Self::LabelOnly;
-        }
         match terminal.name {
             TerminalName::Ghostty
             | TerminalName::Iterm2
             | TerminalName::WezTerm
+            | TerminalName::Rex
             | TerminalName::Kitty
             | TerminalName::VsCode
             | TerminalName::Alacritty

codex-rs/tui/src/markdown_render/web_links_tests.rs

@@ -91,6 +91,7 @@ fn supporting_terminals_render_only_the_styled_label_and_keep_its_target() {
         TerminalName::Ghostty,
         TerminalName::Iterm2,
         TerminalName::WezTerm,
+        TerminalName::Rex,
         TerminalName::Kitty,
         TerminalName::VsCode,
         TerminalName::Alacritty,
@@ -143,21 +144,6 @@ fn supporting_terminals_render_only_the_styled_label_and_keep_its_target() {
     }
 }
 
-#[test]
-fn rex_renders_only_the_label() {
-    let mut rex = terminal(TerminalName::Unknown);
-    rex.term_program = Some("rex".to_string());
-    let markdown = "[label](https://example.com)";
-    assert_eq!(
-        render(
-            markdown,
-            /*width*/ 80,
-            WebLinkDisplay::for_terminal(&rex, /*term*/ None),
-        ),
-        render(markdown, /*width*/ 80, WebLinkDisplay::LabelOnly),
-    );
-}
-
 #[test]
 fn unknown_terminals_and_multiplexers_keep_visible_destinations() {
     let mut tmux = terminal(TerminalName::Ghostty);

codex-rs/tui/src/pets/image_protocol.rs

@@ -178,7 +178,7 @@ fn is_iterm2_terminal(info: &TerminalInfo) -> bool {
 fn supports_kitty_graphics(info: &TerminalInfo) -> bool {
     matches!(
         info.name,
-        TerminalName::Ghostty | TerminalName::Kitty | TerminalName::WezTerm
+        TerminalName::Ghostty | TerminalName::Kitty | TerminalName::Rex | TerminalName::WezTerm
     ) || terminal_field_contains(info.term.as_deref(), "kitty")
         || terminal_field_contains(info.term.as_deref(), "ghostty")
         || terminal_field_contains(info.term.as_deref(), "wezterm")
@@ -516,6 +516,12 @@ mod tests {
                 Some("kitty"),
                 /*term*/ None,
             ),
+            terminal_info_for_test(
+                TerminalName::Rex,
+                /*multiplexer*/ None,
+                Some("rex"),
+                /*term*/ None,
+            ),
             terminal_info_for_test(
                 TerminalName::WezTerm,
                 /*multiplexer*/ None,

codex-rs/tui/src/resize_reflow_cap.rs

@@ -64,6 +64,7 @@ fn auto_resize_reflow_max_rows(
         TerminalName::Alacritty => ALACRITTY_RESIZE_REFLOW_MAX_ROWS,
         TerminalName::AppleTerminal
         | TerminalName::Ghostty
+        | TerminalName::Rex
         | TerminalName::Iterm2
         | TerminalName::WarpTerminal
         | TerminalName::Kitty

codex-rs/tui/src/startup_orchestration.rs

@@ -775,6 +775,7 @@ pub(super) async fn run_main_inner(
         let terminal_name = match terminal_info.name {
             TerminalName::AppleTerminal => "apple_terminal",
             TerminalName::Ghostty => "ghostty",
+            TerminalName::Rex => "rex",
             TerminalName::Iterm2 => "iterm2",
             TerminalName::WarpTerminal => "warp",
             TerminalName::VsCode => "vscode",