feat(cadfs): expand reconstruction capability coverage

backend/engine/cdsl_engine/operation_contracts.py

@@ -30,7 +30,13 @@ def materialized_feature_contracts(profile: dict[str, Any]) -> dict[str, dict[st
         shape = raw.get("fragment_shape")
         params_schema = raw.get("author_params_schema")
         injected_paths = raw.get("server_injected_paths")
-        if not isinstance(shape, dict) or not isinstance(params_schema, dict) or not isinstance(injected_paths, list):
+        selector_policy = raw.get("selector_policy")
+        if (
+            not isinstance(shape, dict)
+            or not isinstance(params_schema, dict)
+            or not isinstance(injected_paths, list)
+            or not isinstance(selector_policy, dict)
+        ):
             raise ValueError(f"operation contract is incomplete for {atomic_id}")
         properties = params_schema.get("properties")
         required = params_schema.get("required")
@@ -51,5 +57,7 @@ def materialized_feature_contracts(profile: dict[str, Any]) -> dict[str, dict[st
             "required_params": materialized_required,
             "optional_params": [name for name in properties if name not in materialized_required],
             "requires_sketch": shape.get("sketch") == "required",
+            "selector_slot": selector_policy.get("slot"),
+            "selector_token_kind": selector_policy.get("token_kind"),
         }
     return derived