• WebGL: reduce max instance count to work around Chrome issues [⚠️ Recompile Materials]
• engine: rework material/shader sampler binding code [⚠️ Recompile Materials]
• engine: add support for specialization constants [⚠️ Recompile Materials]
• gltfio: move the API for recomputeBoundingBoxes [⚠️ API Change]
• gltfio: fix spotlight regression
• gltfio: clear the MaterialInstance cache when creating new instances