fix(lights): synchronize headlight material and shadow with vehicle alarm flashing - #334

Summary

When a parked vehicle's alarm is triggered (m_nAlarmState != 0 && m_nAlarmState != 0xFFFF), GTA SA alternates the headlights and horn in 256ms cycles ((m_nAlarmState & 0x100) != 0).

Previously in ModelExtras:

1. LightManager::Render returned early when the vehicle engine was off during the daytime, completely suppressing the light render loop and resetting m_renderLights.
2. HeadlightComponent::Process and HeadlightComponent::Render did not track m_nAlarmState. As a result, headlight materials and front ground shadows stayed permanently off during daytime alarm sounds and stayed permanently on at night without flashing.

Changes

• In LightManager::Render, allow the render loop to proceed when isAlarmActive is true even if the engine is off.
• In HeadlightComponent::Process and Render, check (m_nAlarmState & 0x100) != 0 to synchronize headlight materials and shadows with the alarm ON/OFF pulse intervals in both daytime and nighttime.
• Preserved existing SA-MP and manual light override behaviors.