c3c27bba5e
CI / changes (pull_request) Successful in 3s
CI / unit (pull_request) Successful in 10s
CI / integration (pull_request) Successful in 14s
CI / ui (pull_request) Successful in 1m2s
CI / conformance (pull_request) Successful in 9s
CI / gate (pull_request) Successful in 0s
CI / deploy (pull_request) Successful in 1m54s
Both hops (backend attachment + gateway /dl forward) wrote the body through net/http's buffered writer, so anything over the write buffer went out Transfer-Encoding: chunked. Android's system DownloadManager — the executor behind VKWebAppDownloadFile — hangs indefinitely on a download of unknown length (observed on-device: VK Android stuck in 'downloading'); Telegram's downloader tolerates chunked, which is why only VK broke. The artifact is fully buffered anyway, so the length is known — set it on both responses.