Bun 1.4.0 (upgraded 0deb607) breaks Telegraf 4.15 sendDocument with
'The socket connection was closed unexpectedly' — reproduced with the same
libraries: Telegraf 4.15.0 on Bun 1.4.0 fails exactly like prod, on Bun 1.3.14
it returns a proper HTTP response. All uploads 500 since the upgrade deployed
(Aug 29 11:06). Pin flake nix override + CI bun-version to 1.3.14.