nx_libindex_gate.nx

nx_libindex_gate.nx -- GATE for the library discovery index (PG1, procgen.plan, 2026-08-24). Composes nx_libindex_lib IN-PROCESS. There is no deployed binary to fork, so the mutation-tester defect where the harness rebuilds the TEST but not the SUBJECT cannot arise here by construction. FIXTURES LIVE IN /tmp/<gate>/, created by sys_mkdir at SETUP -- including the FIXTURE PLANE the build seeds, so the gate never touches the production plane at knowledge/store/libindex-. Estate law, paid for twice: a gate sharing scratch with a production plane reports on the FIXTURE rather than the code, and a teardown does not run when a run crashes, so setup must be the thing that guarantees the clean state. THE LOAD-BEARING TOOTH is finds-a-symbol-that-only-a-library-declares. Everything else here could pass on a broken index; that one is the capability claim itself -- a symbol nx_capsearch was structurally unable to return must be returnable from this plane, or this organ has not closed the gap it was built to close. TWO NEG-CONTROLS AND AN ANTI-VACUITY TOOTH, because an index that swallowed every .nx file would satisfy every positive assertion above while being exactly the wrong artifact.