feat(app): add address-family selection and dual-stack targets

crates/irtt-app/src/cmd/tui/args.rs

@@ -49,7 +49,7 @@ impl TuiArgs {
     ///
     /// The TUI always requires a target: the parser rejects an empty target
     /// list, and this rejects a target set that cannot be labelled uniquely.
-    pub fn prepare(&self) -> Result<ManagedRunSetup, String> {
+    pub async fn prepare(&self) -> Result<ManagedRunSetup, String> {
         prepare_managed_run(
             &self.common,
             self.duration,
@@ -59,6 +59,7 @@ impl TuiArgs {
                 stdin_controlled: false,
             },
         )
+        .await
     }
 
     pub fn is_continuous(&self) -> bool {

crates/irtt-app/src/cmd/tui/run.rs

@@ -34,9 +34,10 @@ pub async fn run_tui(
     args: TuiArgs,
     mut shutdown: watch::Receiver<bool>,
 ) -> Result<(), Box<dyn std::error::Error>> {
-    let setup = args
-        .prepare()
-        .map_err(|err| io::Error::new(io::ErrorKind::InvalidInput, err))?;
+    let setup = tokio::select! {
+        result = args.prepare() => result.map_err(|err| io::Error::new(io::ErrorKind::InvalidInput, err))?,
+        _ = shutdown.wait_for(|requested| *requested) => return Ok(()),
+    };
     let continuous = args.is_continuous();
     if *shutdown.borrow() {
         return Ok(());