feat(tui): optimize performance by caching display lines and token counts, and improve action handling

apps/interfaces/tui/src/turn.rs

@@ -19,11 +19,12 @@ use crate::state::AppStateRest;
 
 /// Spawn an agent turn on a background OS thread.
 pub fn spawn_agent_turn(state: &mut AppStateRest, text: String) {
-    if let Ok(mut in_flight) = state.turn_in_flight_flag.lock() {
-        if *in_flight {
-            return;
-        }
-        *in_flight = true;
+    // compare_exchange: only mark in-flight if not already running
+    if state.turn_in_flight_flag
+        .compare_exchange(false, true, Ordering::SeqCst, Ordering::Relaxed)
+        .is_err()
+    {
+        return; // already running
     }
 
     let turn_events = state.turn_events.clone();
@@ -56,7 +57,7 @@ fn run_turn(
     session_dir: &Path,
     workspace_roots: &[PathBuf],
     turn_events: &Arc<Mutex<VecDeque<TurnEvent>>>,
-    in_flight: &Arc<Mutex<bool>>,
+    in_flight: &Arc<AtomicBool>,
     abort: &Arc<AtomicBool>,
 ) {
     let client = LlmClient::new(
@@ -188,8 +189,7 @@ fn push_event(queue: &Arc<Mutex<VecDeque<TurnEvent>>>, event: TurnEvent) {
     }
 }
 
-fn mark_done(flag: &Arc<Mutex<bool>>) {
-    if let Ok(mut f) = flag.lock() {
-        *f = false;
-    }
+/// Mark the turn as done using lock-free atomic store.
+fn mark_done(flag: &Arc<AtomicBool>) {
+    flag.store(false, Ordering::SeqCst);
 }