Sync GPU OBJ mapping APIs across versions

[xiangao0904]

Summary

This PR syncs the GPU OBJ mapping APIs across Fabric/Forge versions and expands the optimized rendering pipeline to support atlas-aware raw OBJ loading and generic instanced rendering helpers.

What changed

• Unified OptimizedModel, OptimizedRenderer, ObjModelLoader, and related rendering helpers across multiple mappings/versions.
• Added atlas-aware raw OBJ loading support.
• Added reusable instanced rendering helpers and low-level buffer/VAO/vertex attribute utilities.
• Introduced GL state tracking and shader/material helpers to keep optimized rendering stable across versions.
• Fixed full-version OBJ handling and mapped-method checks.
• Added/updated tests for OBJ model behavior and mapping validation.

Notes

• This is mainly a cross-version API/mapping sync plus rendering infrastructure update, not a single-feature change.
• The changes are aimed at reducing version-specific divergence and making the optimized GPU OBJ path more consistent.