fix(tui): reset user_scrolled_during_stream on stall recovery

Without this, the turn immediately after a stall recovery would inherit
the scroll-lock from the stalled turn and silently skip auto-scroll,
leaving the user staring at stale content.

crates/tui/src/tui/ui.rs

@@ -3930,6 +3930,8 @@ fn reconcile_turn_liveness(app: &mut App, now: Instant, has_running_agents: bool
         app.runtime_turn_status = None;
         app.runtime_turn_id = None;
         app.dispatch_started_at = None;
+        // Per-turn scroll lock — clear so the next turn auto-scrolls.
+        app.user_scrolled_during_stream = false;
         app.push_status_toast(
             "Turn stalled — no completion signal received. Please try again.",
             StatusToastLevel::Error,

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

@@ -2040,6 +2040,7 @@ fn turn_liveness_recovers_stalled_in_progress_turn() {
     app.turn_started_at =
         Some(Instant::now() - TURN_STALL_WATCHDOG_TIMEOUT - Duration::from_millis(1));
     app.streaming_message_index = Some(0);
+    app.user_scrolled_during_stream = true;
 
     let recovered = reconcile_turn_liveness(&mut app, Instant::now(), false);
 
@@ -2051,6 +2052,7 @@ fn turn_liveness_recovers_stalled_in_progress_turn() {
     assert!(app.dispatch_started_at.is_none());
     assert!(app.streaming_message_index.is_none());
     assert!(app.streaming_thinking_active_entry.is_none());
+    assert!(!app.user_scrolled_during_stream);
     let toast = app.status_toasts.back().expect("stall toast");
     assert_eq!(toast.level, StatusToastLevel::Error);
     assert!(toast.text.contains("Turn stalled"));