Ports the novel per-session empty-My-Packs capability negotiation — proven live
on staging and currently Python-only (fifa17-recon/tools/utas_server.py) — into
the production Rust FIFA17 adapter as a pure, dependency-free state machine
(openfut-adapter-fifa17 fut::store_session).
It owns: per-login X-UT-SID session table, single-use (ip,persona) launcher
capability hand-off (pending), capability binding (bound/pending/ignored-late),
the once-per-session clean-v1 vs sentinel freeze, TTL reaping, and fail-closed
rules (unknown/expired/ambiguous/late/cross-session/sid-ip-mismatch -> sentinel).
The clock and SID entropy are injected so it is fully unit-testable.
The full Python capability-negotiation matrix A-R is ported as Rust unit tests
(21 pass). Python remains the behavioural oracle. The delicate _pack_body UTAS
wire shaping, /ut/auth persona-adoption, /store/purchasegroup catalogue assembly
and the store BUY path are deliberately NOT ported here (documented gap); wiring
the three routes into openfut-utas-host without splitting store authority is the
remaining bounded slice toward full Rust authority. No production deployment.
funman300