fix(r2): return source digest/size for mounted blob HEAD responses#121

mushanyoung wants to merge 2 commits into

cloudflare:maincloudflare/serverless-registry:mainfrom

mushanyoung:fix/r2-mounted-blob-head-metadatamushanyoung/serverless-registry:fix/r2-mounted-blob-head-metadataCopy head branch name to clipboard