fix(core): relocate heliRenderEvent hook from CEntity to CHeli and guard vehicle types

[CanerKaraca23]

Summary

Fixes an Access Violation crash (0xC0000005 at 0x004C5B10 in CModelInfo::IsHeliModel) that occurs in total conversion mods or expanded limit configurations (such as SAxVCxLC) when rendering map objects/buildings with model IDs above 32,767.

Root Cause

1. In src/utils/meevents.h, heliRenderEvent was hooked at 0x5343B2 (call CEntity::RenderEffects inside CEntity::Render).
2. CEntity::Render() is the base render routine for all non-vehicle world entities (buildings, objects, roads, and dummies) across the entire map. As a result, every rendered map entity was triggering heliRenderEvent and being passed to the lambda as a CVehicle*.
3. In src/utils/modelinfomgr.cpp, the callback queried CModelInfo::IsHeliModel(pVeh->m_nModelIndex).
4. Because CEntity::m_nModelIndex is defined as a signed 16-bit short, any model ID > 32,767 (e.g. 34,569 = 0x8709) sign-extends to a negative integer (-30,967 / 0xFFFF8709).
5. CModelInfo::IsHeliModel indexed ms_modelInfoPtrs with that negative index, causing an immediate crash.

Changes

1. Hook Relocation (src/utils/meevents.h):
   • Moved heliRenderEvent from 0x5343B2 to 0x6C4523 (call CEntity::Render at the tail of CHeli::Render).
   • 0x6C4523 is exclusively called for helicopters, eliminating tens of thousands of redundant event firings per frame on map objects and significantly improving rendering performance.
2. Defensive Entity Guards (src/utils/modelinfomgr.cpp):
   • Added pVeh->m_nType == ENTITY_TYPE_VEHICLE checks to both vehRenderEvent and heliRenderEvent.
   • Cast m_nModelIndex to unsigned uint16_t before calling CModelInfo::IsHeliModel().
   • Added standard 10-frame dummy registration (ModelInfoMgr::FindDummies) for helicopters.