nx_seat_drive.nx

nx_seat_drive.nx -- S2 SEAT-PROTOCOL DRIVER (agent-seat system, 2026-07-20). Runs the seat lifecycle around a lane-configured work step so a NON-CLAUDE seat (local maker ensemble, cron, any executor) closes rungs through the same protocol and gates as a Claude seat: CHECKIN -> WORK -> VERIFY(gate) -> CHECKOUT, with an append-only journal (fa_appendz, torn-proof) as the resume/standup surface. Single responsibility: the PROTOCOL. The work itself, its success gate, and the hub verbs are all LANE CONFIG DATA (no magic behavior, rule 11/22). argv: <lanefile> lanefile = KEY=VALUE lines (LF). Required: ws= actor= journal= workelf= workartifact= gateelf= Optional: workarg1..workarg3, gatearg1..gatearg2, checkinelf= checkinarg1=, checkoutelf= checkoutarg1= Hub-verb convention: checkin/checkout elfs are invoked as <elf> [argN] <ws> <actor> so a live wrapper (nx_seat checkin over tools/call) and a fixture both fit. ARTIFACT-TRUTH (banked law): the work step is judged by its DECLARED artifact (workartifact unlinked before the run, must exist non-empty after), not only by wait4 status. A work step that "succeeds" without producing its artifact is REFUSED. exit: 0 OK | 2 config | 3 checkin-refused (fail-closed) | 4 work-fail | 5 gate-RED 6 artifact-missing | 7 checkout-fail license_tier: ORIGINAL No hw writes (Rule 26).