matrix-nio 0.26 dropped the withOlm/python-olm arguments, breaking the
override and every nixos-yellow CI check since the last flake.lock update.

Fork carried only fix/pmtu-blackhole-recovery on a base now 167 commits
behind upstream. Upstream has since landed the principled successors
(pmtu revalidate-idle-UDP, sub-MINMTU convergence, UDPDiscoveryTimeout
floor, gossip dedup purge). tinc-crypto now links openssl-sys, so add
pkg-config + openssl.

Measured with ipfs-check against a pinned CID: DHT record present,
bitswap answering, no IPNI record, and every public gateway 504ing on
anything bigger than one block -- a DAG walked block by block over
bitswap from a single peer does not fit their request budget. The old
node (2configs/services/flix/ipfs.nix) ran Routing.Type autoclient,
which announces to cid.contact as well as the DHT, plus Provide
strategy pinned; mirror that and its swarm sizing.

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.