nx_seat_hub.nx

nx_seat_hub.nx -- S2b HUB-FRAME WRAPPER (agent-seat system, 2026-07-20). Fronts the LIVE hub's `nx_seat checkin/checkout` over sovereign MCP tools/call so a non-Claude seat's claim + kickoff/done frames land on the SAME board a Claude seat uses. Fits nx_seat_drive's hub-verb convention: <elf> <hubconf> <ws> <actor> hubconf = KEY=VALUE lines: mcpelf= url= capfile= verb=checkin|checkout ttl= note= outfile= (ttl required for checkin only; everything is config DATA -- rule 11/17.) FAIL-CLOSED BY BODY-PARSE (banked law: transport can lose RESPONSES and exit codes lie through relays -- only the hub's own printed markers count, probed LIVE 2026-07-20): checkin success marker = "claim=HELD" (contended prints claim=CONTENDED -> refuse) checkout success marker = "done=1" Missing marker, empty body, or transport failure -> exit 3 (the driver's refused-claim class). license_tier: ORIGINAL No hw writes (Rule 26).