fix(maestro): wait for settle in pristine natural-exit test

Dead status is observable a moment before the settle step removes the
worktree, so the assertions raced the removal under parallel load. Wait
for the tree to be gone and the store to stay empty, same as the
retained-store wait cfebfd4 added to the guarded sibling.

Fixes #113

crates/maestro-daemon/tests/session_manager.rs

@@ -848,6 +848,17 @@ async fn natural_exit_of_a_pristine_worktree_removes_it() {
     })
     .await;
 
+    // (`Dead` is observable a moment before the settle step removes the tree.)
+    wait_for_async(Duration::from_secs(3), || async {
+        !wt_path.exists()
+            && fx
+                .retained_store()
+                .load_all()
+                .map(|all| all.is_empty())
+                .unwrap_or(false)
+    })
+    .await;
+
     assert!(
         !wt_path.exists(),
         "a pristine worktree leaves nothing behind"