nx_wflow_obs_gate.nx

nx_wflow_obs_gate.nx -- R6 RUN OBSERVABILITY gate: the board + 0-JS HTML run page are derived ENTIRELY by replaying the event-sourced run ledger (nothing self-reported). Builds a mixed ledger through REAL engine calls (one DONE run, one FAILED run, one PARKED-on-approval run, one synthetic in-flight RUNNING), then asserts the derived states, the totals, and the real page bytes (title + states present, zero <script, DOCTYPE-led). Neg-controls: empty ledger reports 0 runs (no fabrication); nonsense state absent. ZERO forks. license_tier: ORIGINAL expect_exit: 0