Make scene layer random seeds reproducible

tools/prompt_smoke.py

@@ -15980,6 +15980,32 @@ def smoke_node_scene_chain_registration() -> None:
         _expect(node_name in sxcp_nodes.NODE_DISPLAY_NAME_MAPPINGS, f"{node_name} missing from display registry")
 
     nodes = sxcp_nodes.NODE_CLASS_MAPPINGS
+    random_seed_options = nodes["SxCPSceneLayerSeedOptions"]().build(
+        "softcore_branch",
+        "random",
+        123456789,
+        "content_pose",
+        "same_for_all_rows",
+        "replace_layer",
+    )[0]
+    fixed_seed_options = nodes["SxCPSceneLayerSeedOptions"]().build(
+        "softcore_branch",
+        "fixed",
+        123456789,
+        "content_pose",
+        "same_for_all_rows",
+        "replace_layer",
+    )[0]
+    random_seed_item = json.loads(random_seed_options)["items"][0]
+    fixed_seed_item = json.loads(fixed_seed_options)["items"][0]
+    _expect(
+        random_seed_item.get("seed") == 123456789,
+        "Scene random layer seed should use the visible node seed",
+    )
+    _expect(
+        random_seed_item.get("seed") == fixed_seed_item.get("seed"),
+        "Scene random and fixed layer seeds should match when the visible seed matches",
+    )
     scene, start_summary, _start_metadata = nodes["SxCPSceneStart"]().build(
         1,
         41,