[Test logic] Controller scenario never asserts volume / muted in server/state

[balloob]

Problem

The spec defines controller.volume (0-100) and controller.muted (bool) in the server/state controller object. The harness:

• Surfaces them in client_summary.controller.received_state.volume / muted (see aiosendspin_client.py:151-158 _normalize_controller_state).
• Surfaces them on the server side too (aiosendspin_server.py:497-502).
• Never compares them — runner.py:684-697 _compare_controller_summaries only asserts expected == received == sent for the command.

So a server that lies about volume (or omits muted) passes the controller scenario.

Proposed fix

1. Extend _compare_controller_summaries to assert the client's received_state.volume and muted equal the server's reported values.
2. Parameterize the controller scenario (or add new scenarios) to cover non-default values — volume=37, muted=true, etc.

Spec references

• "Server → Client: server/state controller object"
• "Reading group volume" / "Reading group mute"