ComfyUI upstream source

Immutable ComfyUI source with a Bazel CPU entry point

ComfyUI v0.43.0 is pinned at commit 426f5eea52a7ece1dd599fff4cb6cd1f352ddd24. The archive integrity is computed from the upstream codeload archive. The BUILD overlay packages unmodified upstream code and runtime resources; dependencies are owned by tools/comfyui/uv.lock. Upstream code remains licensed under GPL-3.0.