feat(pi-extension): add status bar indicator for ponytail mode (closes #84) (#275)

Add a syncStatus function to Pi extension to display the current
Ponytail mode in the status bar.

The indicator updates upon mode changes and hooks into the agent_start
and agent_end events to display a visual active/inactive state.
This provides the user with clear feedback on the currently active
Ponytail intensity level (lite, full, ultra) without running commands.