Default to retained history with a separate pending count, and add persistent display.inbox CLI modes for history, pending, and unread. Preserve browsing while clients are connected and show the active USB or Bluetooth connection.
Fixes#5
Persist separate display modes and timeouts in seconds for battery and USB power, expose four controls in WebConfig and CLI, and apply one shared policy across display-equipped roles.
Detect R8 external power from a USB host or calibrated battery voltage above 4.21 V, with cached sampling and hysteresis. Add policy, persistence, browser, and R8 power-detection regression coverage.
mikecarper