A way to get watch battery information

Feature description

Provide a way to get watch's battery state, with the same reason wy we would want phone's battery state.

Reference implementation

Have you checked if the feature is accessible through the Android API?
Not really, but it's seems clear we will need a termux:API variant for wear os.
See https://stackoverflow.com/questions/25884383/get-battery-level-of-connected-smartwatches

Do you know of other open-source apps that has a similar feature as the one you want? (Provide links)
Not in open source, but you may want to talk with the developer of this app to get some help if needed :
Phone battery, it adds a widget to see the watch battery state: https://play.google.com/store/apps/details?id=com.ppltalkin.phonebatterylevel
developer's registered mail: ppltalkin@gmail.com

Start by checking whether the Android or Wear OS API exposes the connected watch's battery state, using the linked Stack Overflow discussion and reference app for context. Done means providing a Termux:API variant that lets callers retrieve the watch battery state, with behavior documented or tested as appropriate.