unsloth/async_task_outputs/async_task_output_eubt71.md

• Decision: stacked Phase 16 on diffusion-phase15-int8-prequant because current workspace HEAD was Phase 15 (9c5b35c71) and PR needed to continue the chain.
• Decision: staged only the 11 intended feature/test files and deliberately excluded local benchmark tooling/logs/plans to keep PR scope clean.
• Created branch diffusion-phase16-native-engine-routing from diffusion-phase15-int8-prequant.
• Committed 7f3c206fa with message Studio diffusion (Phase 16): route no-GPU loads to the native sd.cpp engine.
• Files committed: /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/studio/backend/core/inference/diffusion_engine_router.py, /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/studio/backend/core/inference/diffusion_families.py, /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/studio/backend/core/inference/gpu_arbiter.py, /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/studio/backend/core/inference/sd_cpp_backend.py, /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/studio/backend/core/inference/sd_cpp_engine.py, /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/studio/backend/models/inference.py, /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/studio/backend/routes/inference.py, plus 4 test files including studio/backend/tests/test_diffusion_engine_router.py and studio/backend/tests/test_sd_cpp_backend.py.
• Created PR body file /mnt/disks/unslothai/ubuntu/workspace_81/unsloth/temp/phase16_pr_body.md.
• Ran gh auth status; key output: logged in to github.com as danielhanchen using GH_TOKEN.
• Ran git checkout -b diffusion-phase16-native-engine-routing; exit success, output Switched to a new branch 'diffusion-phase16-native-engine-routing'.
• Ran git commit; exit success, output 11 files changed, 1241 insertions(+), 27 deletions(-), created 4 new files.
• Ran git push -u origin diffusion-phase16-native-engine-routing; exit success, branch pushed to https://github.com/unslothai/unsloth.git; remote noted GitHub found 19 vulnerabilities on unslothai/unsloth's default branch.
• Ran gh pr create --repo unslothai/unsloth --base diffusion-phase15-int8-prequant --head diffusion-phase16-native-engine-routing --title "Studio diffusion (Phase 16): route no-GPU loads to the native sd.cpp engine" --body-file temp/phase16_pr_body.md; output warning Warning: 20 uncommitted changes, then created https://github.com/unslothai/unsloth/pull/6724.
• Ran gh pr view 6724 --repo unslothai/unsloth --json number,title,state,baseRefName,headRefName,additions,deletions,changedFiles,url; verified PR #6724 is OPEN, base diffusion-phase15-int8-prequant, head diffusion-phase16-native-engine-routing, +1241/-27 across 11 files.
• Completed: Phase 16 PR created and verified at https://github.com/unslothai/unsloth/pull/6724.
• Completed: summary noted prior validation: sd.cpp fastest CPU engine vs diffusers/ComfyUI; CPU/Mac Studio auto-routes to sd.cpp with diffusers fallback; 313 tests green + real CPU end-to-end validated; external comparisons written in outputs/ext_engines/SUMMARY.md, FINAL_engine_comparison.md, and coverage_matrix.md.
• Pending: CI on PR #6724 still needs to run/be watched; user was asked whether to watch checks and reconcile failures.