Add StatsManager for single display

src/seedpass/core/stats_manager.py

@@ -0,0 +1,20 @@
+"""Manage display of stats screens."""
+
+from __future__ import annotations
+
+
+class StatsManager:
+    """Track whether stats have been displayed."""
+
+    def __init__(self) -> None:
+        self._displayed = False
+
+    def display_stats_once(self, manager) -> None:
+        """Display stats using ``manager`` once per reset."""
+        if not self._displayed:
+            manager.display_stats()
+            self._displayed = True
+
+    def reset(self) -> None:
+        """Reset the displayed flag."""
+        self._displayed = False