test(charging-station): add lifecycle prototype test to validate mocking strategy

test(charging-station): add lifecycle prototype test to validate mocking strategy

- Create ChargingStation.test.ts with minimal test structure
- One test: validates station instantiation and start() state transition
- Uses createRealChargingStation() from test utilities
- Proper cleanup with afterEach hook
- BLOCKING validation passed - mocking strategy confirmed working
- Fix ESLint errors: proper ChargingStation type import