fix(tui): launch feedback urls asynchronously

Keep feedback URL launching off the UI path so feedback actions do not stall interactive input.

crates/tui/src/tui/ui.rs

@@ -4735,19 +4735,18 @@ async fn apply_command_result(
 
 #[cfg(any(target_os = "macos", target_os = "linux", target_os = "windows"))]
 fn open_external_url(url: &str) -> Result<()> {
-    let mut command = external_url_command(url);
+    spawn_external_url_command(external_url_command(url))
+}
 
-    let status = command
+#[cfg(any(target_os = "macos", target_os = "linux", target_os = "windows"))]
+fn spawn_external_url_command(mut command: Command) -> Result<()> {
+    command
+        .stdin(Stdio::null())
         .stdout(Stdio::null())
         .stderr(Stdio::null())
-        .status()
-        .map_err(|err| anyhow::anyhow!("failed to launch browser command: {err}"))?;
-    if !status.success() {
-        return Err(anyhow::anyhow!(
-            "browser command exited with status {status}"
-        ));
-    }
-    Ok(())
+        .spawn()
+        .map(|_| ())
+        .map_err(|err| anyhow::anyhow!("failed to launch browser command: {err}"))
 }
 
 #[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "windows")))]

crates/tui/src/tui/ui/tests.rs

@@ -2220,6 +2220,34 @@ fn event_poll_timeout_has_nonzero_floor() {
     );
 }
 
+#[test]
+#[cfg(any(unix, windows))]
+fn external_url_launcher_does_not_wait_for_browser_process() {
+    let command = slow_external_url_command();
+    let start = Instant::now();
+
+    spawn_external_url_command(command).expect("spawn external URL command");
+
+    assert!(
+        start.elapsed() < Duration::from_millis(750),
+        "opening a feedback URL must not wait for the browser command to exit"
+    );
+}
+
+#[cfg(unix)]
+fn slow_external_url_command() -> Command {
+    let mut command = Command::new("sh");
+    command.args(["-c", "sleep 1"]);
+    command
+}
+
+#[cfg(windows)]
+fn slow_external_url_command() -> Command {
+    let mut command = Command::new("cmd");
+    command.args(["/C", "ping -n 2 127.0.0.1 >NUL"]);
+    command
+}
+
 #[test]
 fn footer_status_line_spans_show_mode_and_model_idle_and_active() {
     let mut app = create_test_app();