optimize-image-upload-pipeline

The slow path starts before the image preview renders, so the UI waits on compression even when the original file could be shown immediately.

I'm separating optimistic preview rendering from optimization so the original image can paint immediately while background work continues.

The queue now creates an optimistic preview immediately, then waits for worker metadata before swapping in the optimized asset.

I moved the CPU-heavy compression work into a dedicated worker and kept the selected image state in the main upload flow.

I added retry boundaries around signed URL creation so failed uploads can restart without losing the selected image.

The legacy upload worker duplicated retry orchestration and kept stale blob references alive, so I removed it and folded the remaining state transitions into the pipeline.

The dropzone now keeps the preview responsive while retries happen in the background.

The regression test now covers immediate preview rendering, worker completion, and recovery from a failed signed URL request on a large image upload.

The upload pipeline changes are ready for review. I attached the worker split, retry boundary, and regression test updates to the pull request.