Mechanical-move plan: lift TextureKey out of the GL atlas class, move the
ObjectMeshData family, extract the Prepare* CPU pipeline verbatim into a
new MeshExtractor in AcDream.Content (net10.0, no Silk.NET), App keeps
queue/worker/upload lifecycle and delegates. Binding rules: verbatim
bodies (no SurfaceDecoder switch - byte-identity is MP1b conformance
foundation), compiler enumerates dependencies, BLOCKED on any hidden GL
dependency, zero divergence rows. Gates: full suite green per task +
user launch smoke. Boundary facts verified against source this session:
the Prepare* region touches GL only via the TextureKey struct; first GL
call is UploadGfxObjMeshData.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>