The contributor's regression test for Feishu fallback thread routing
asserted on attributes specific to the real lark SDK builder
(call_args.body, body.receive_id). In test environments without the
lark SDK installed, the in-tree fallback (gateway/platforms/feishu.py
_build_create_message_request) returns a SimpleNamespace using
.request_body instead of .body, causing AttributeError.
Now reads via getattr fallback and also verifies receive_id_type is
'thread_id' (not 'chat_id') as a stronger contract check.
f9e0d60a99