Reddit report: the header power toggle switches correctly but
displays "backwards" - the button shows the action a click would
perform (e.g. "Aus" while the printer is on), not the printer's
actual current state, which some users find counterintuitive.
Both readings are legitimate, so this adds a per-printer opt-in
(Settings -> Power Switch -> "Aktuellen Status statt Aktion
anzeigen") rather than flipping the default for everyone.
power_status_inverted=0 (default) keeps today's behavior; =1 mirrors
the actual on/off state instead. The backend's power-status parsing
is untouched - only _applyHeaderPowerState() picks which state to
display, so the click handler still always toggles the real state
regardless of display mode.
(Same fix as testing branch commit 7d28ed4, applied manually here
since nightly still has the pre-mixin-split monolithic
kobrax_moonraker_bridge.py layout - bridge_endpoints.py doesn't exist
on this branch yet.)