Each pair runs the work as the renderer always has and reads the result back, or makes the same
textures and fills them from bytes instead: impostor_bytes / impostor_from_bytes (and impostor_fill,
for a fog that opens past a layer's cards), terrain_shadow_bytes / terrain_shadow_from_bytes,
sky_ibl_bytes / sky_ibl_from_bytes (sky_precompute split into sky_ibl_make and the convolutions).
A bundle is a word count, a word length per part and the parts (bake_pack / bake_unpack), checked
against the textures' shapes before any byte is used. gpu_vk_readback.ludic reads a texture's level 0,
every layer, as stored; r3d_baked_read reads a bake's file (ludic.base's LBAK header: key and version
must match) since render3d cannot import ludic.base. Nothing calls them yet: behaviour unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
