fix(charging-station): add try/finally guards to lifecycle methods

fix(charging-station): add try/finally guards to lifecycle methods

Prevent zombie state flags when exceptions occur:
- start(): wrap in try/finally to always reset starting=false
- stop(): wrap in try/finally to always reset stopping=false
- reset(): catch stop() failure and abort instead of proceeding
  with sleep+start on a half-stopped station
- delete(): catch stop() failure so cleanup always proceeds