nx_ecomat_seed_clobber_gate.nx

nx_ecomat_seed_clobber_gate.nx -- proves the ANTI-CLOBBER guard in nx_ecomat_seed BITES. ★WHY (measured 2026-08-07). ss_commit REPLACES a plane with the write-set handed to it (nx_ecomat_put.nx:66, gate-proven). nx_ecomat_seed authors its domains from SOURCE and never reloads, so the moment the live plane carries a domain the source does not author, running the seeder DELETES it. Measured that day: the live plane held 26 domains, the laptop source authored 23 and the NAS source 22 -- so either one destroyed 3-4 domains AND REPORTED GREEN, because the success check was a hardcoded `ver == N` equality that had been hand-edited down to match. ★THE GUARD IS KEYED ON IDENTITY, AND THIS GATE'S JOB IS TO PROVE THAT DISTINCTION IS REAL. A count-based shrink refusal was built in the SHARED PRIMITIVE on 2026-08-02 and reverted before promote (nx_store_seed_lib.nx:207) because it broke legitimate whole-plane rewriters. Debt 1785710884 concluded such a guard belongs at the PLANE-WRITER layer. T5 below is the anti-vacuity tooth for exactly that: a plane whose ROW COUNT SHRINKS but whose every NAME survives must still be ALLOWED. A naive count-based reimplementation passes T1-T4 and FAILS T5, which is the point -- a tooth the trivial wrong implementation can also pass proves nothing. Forks the REAL resolved nx_ecomat_seed.elf via ar_resolve (never a hardcoded path -- the 127-vacuous lesson), so what is proven is the artifact that actually runs. T0 asserts the subject was FOUND, because an absent artifact (exit 127) is indistinguishable from a passing refusal. license_tier: ORIGINAL expect_exit: 0