Bake v2 exporter side: library/preset, legacy scene-material, and item-GLB
textures get a validated pascalTextureRef stamped at load (origin-checked,
env-derived). Material-ish sources resolve to 'library-material' (storage
bucket) or 'app-material' (static catalog on the assets CDN) by URL shape.
exportSceneToGlb grows a textures: 'embed' | 'reference' option — reference
mode swaps stamped textures for 1x1 canvas-backed placeholders (skipping the
WebGPU blit) and writes the ref to both texture and image extras via a
GLTFExporter writeTexture plugin. Download GLB stays embed; the bake page
passes reference.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
