step 8: harden docs and prepare rebuilt beta

src/dpg_map/state.py

@@ -276,6 +276,13 @@ def resolve_map_tag(map_tag: Tag | None = None) -> Tag:
     raise MapNotFoundError("map_tag is required outside a map_widget context")
 
 
+def list_map_states() -> list[MapState]:
+    """Return registered map states as a snapshot."""
+
+    with _maps_lock:
+        return list(_maps.values())
+
+
 def find_map_for_overlay(tag: Tag, map_tag: Tag | None = None) -> MapState:
     """Find the map containing an overlay, optionally scoped by map tag."""