feat: Show the battery and Wi-Fi of each speaker in the system info

[abusch]

Adds each speaker's battery and Wi-Fi to the system info (i), from the hardwareStatus namespace of sinuous-client 0.2.2.

│ Battery       100% (measured 91%) · charging · on its charger · 27.0 °C
│ Wi-Fi         <network> · good
│ Access point  <bssid> · 5 GHz · channel 64 · signal 25

• Battery, for portable speakers, which are the only ones reporting one: the charge (and the measured charge when it differs), whether it's charging or on its charger, and its temperature. It's red below 20% when not charging.
• Wi-Fi: the network and connection health, then the access point's BSSID, band, channel and signal (as Sonos reports it, higher is better, not in dBm). Speakers that haven't reported it, e.g. wired ones, show "not reported".
• Each speaker's hardware status is subscribed to, and the latest battery and Wi-Fi status are kept on PlayerInfo, across topology changes like volumes.

Tried read-only against a real household: all five speakers reported their Wi-Fi, and both portable ones their battery, without subscription errors.

🤖 Generated with Claude Code