With proxy_request_buffering off, nginx sizes the HTTP/2 per-stream flow
control window to max(client_body_buffer_size, http2_body_preread_size).
The 64 KiB default capped uploads at 64 KiB / 55 ms RTT = 1.2 MB/s while the
backend read slower than the client sent. Set client_body_buffer_size 8m for
the upload location; streaming (no disk spool) and timeouts are unchanged.

Warez-style hand-drawn logo, IBM VGA webfont inlined for exact
full-width scaling without JS, light/dark schemes, clickable nix
attrset profile with project links, robots.txt and eval-able
/profile.nix.

openai-agents 0.18.1 gained a websockets runtime dep that nixpkgs does not
declare yet, and nixpkgs' openai 2.53.0 is past omnigent's <2.45 cap.

jellyfin only listens on IPv4, but yellow.r also resolves to its
retiolum AAAA. nginx round-robined both addresses, so requests
hitting the v6 upstream failed and poisoned the upstream group,
causing intermittent 502 'no live upstreams' on flix.lassul.us.

Also drop the stale duplicate flix vhost from container-host.nix.