Buzzer sounds to represent statuses

The buzzer should be used to inform us of errors and statuses. Implement the following, sounds are in dash dot notation like morse

- tracker is on -> _ _ _
- tracker received radio packet -> .
- tracker is being aimed (packet contains both gnss and alt, tracker has mag data, gnss data and alt data) -> _

Start by locating the buzzer control and the status-handling entry points in the C source; the issue does not name specific files or tests. Trace how power-up, radio-packet reception, and aiming state are represented, then verify that each state produces the specified dash-dot sound pattern on the hardware.

Written by the indexing model from the issue text.