ClawMetry Asimov observation support

The data-only LiveKit connection method in observer.py is adapted from
Menlo SDK 0.1.0, Copyright 2026 Menlo Research Pte. Ltd., licensed under
the Apache License, Version 2.0. The adaptation disables automatic media
subscription and requires explicit receive-only data authority.

Original source:
https://github.com/menloresearch/menlo-sdk/blob/568385a5a03212303b876ff7e4d77833ab55c7d8/src/menlo/asimov/transport/_livekit_client.py

The Apache 2.0 license text is included in LICENSE-MENLO.
