Openclaw (AI): Follow-up to #778 for Allen's final post-merge typing/style nit.

This keeps the existing B01 behavior but narrows send_decoded_command() away from Any to a concrete response alias:

DecodedB01Response = dict[str, object] | str

Why each type exists:

• dict[str, object]: used for decoded query-style responses where data is structured content, e.g. prop.get, service.get_map_list, and other read/query helpers that parse fields from the returned payload.
• str: used for raw command ACK responses where the device returns a plain success token like "ok", e.g. action-style commands such as clean/start/pause/stop flows that only need acknowledgement rather than structured data.

The point of this follow-up is to make the return shape more explicit for callers/reviewers without over-constraining it to dict and regressing the existing ACK path.

Validation:

• ./.venv/bin/pytest -q tests/devices/traits/b01/q7/test_init.py
• ruff check roborock/devices/rpc/b01_q7_channel.py tests/devices/traits/b01/q7/test_init.py