fix: occupied cells sorted by agent_order, assertion to verify best m…

…oves aren't duplicated

examples/sugarscape_ig/ss_polars/agents.py

@@ -200,16 +200,20 @@ def get_best_moves(self, neighborhood: pl.DataFrame, agent_order):
             )
             .drop("agent_order")
         )
+assert best_moves.n_unique() == len(
+            best_moves
+        ), "Duplicates found in best_moves"
         return best_moves
 
     def _prepare_cells(self, neighborhood: pl.DataFrame):
         occupied_cells = (
-            neighborhood[["agent_id_center"]]
+            neighborhood[["agent_id_center", "agent_order"]]
             .unique()
             .join(self.pos, left_on="agent_id_center", right_on="unique_id")
             .with_columns(
                 flattened=(pl.col("dim_0") * self.space.dimensions[1] + pl.col("dim_1"))
-            )["flattened"]
+            ).sort("agent_order")
+["flattened"]
             .to_numpy()
         )
         free_cells = np.ones(