//! Runtime GPU resource management for `MtlContext`. The methods are split
//! across sibling files by resource family:
//!
//! textures.rs albedo + normal-map pool slot updates, IBL envmap +
//! color-grading LUT hot-swap
//! geometry.rs Streamed-mesh upload / eviction via the sub-allocators, and
//! in-place per-slot geometry replacement
//! streaming.rs `VoxelWorld` chunk streaming
//! skinning.rs skinned pipelines + buffer setup, per-frame pose updates,
//! and skinned hot-reload paths
//! geometry_rebuild.rs `rebuild_static_geometry` -- hot-reload rebuild of the
//! shared static vertex + index buffers
//!
//! Each file is a single `impl MtlContext { pub fn ... }` block; nothing is
//! re-exported here -- callers reach the methods directly through `MtlContext`.
pub