feat: native sandbox execution, dynamic review middleware, and workspace files

Adds native sandbox execution runtime, dynamic review middleware, and
workspace file handling, with supporting stream events, prompt, and scope
registry changes plus architecture docs.

tests/test_langgraph_dev_http.py

@@ -210,8 +210,8 @@ def test_workspace_scope_routes_require_service_token():
     assert response.status_code == 401
 
 
-def test_workspace_materialize_rejects_path_escape():
-    from EvoScientist.langgraph_dev.http import _materialize_target
+def test_workspace_path_rejects_escape():
+    from EvoScientist.workspace_files import normalize_workspace_path
 
-    with pytest.raises(ValueError, match="uploads"):
-        _materialize_target(str(uuid4()), "../secret.txt")
+    with pytest.raises(ValueError, match="workspace"):
+        normalize_workspace_path("/workspace/../secret.txt")