nx_enginelab_gate.nx

nx_enginelab_gate.nx -- END-TO-END gate for the sovereign engine instrument. WHAT A GREEN HERE MEANS, AND WHAT IT DOES NOT. Every tooth below asserts an ARITHMETIC property of the instrument on a fixture built at runtime inside this process. A green says the five instrument classes compute what they claim on data whose right answer is known by construction. It says NOTHING about any engine's real performance -- that is the instrument's job, not the gate's. FIXTURES ARE BUILT IN MEMORY, NEVER ON DISK AND NEVER SHARED. A gate that shares scratch with a production beat measures the fixture instead of the code (this estate has the receipt: a segguard fold took a gate RED while the same code went 24/24 GREEN on private scratch). Nothing here opens a file, so there is no teardown to skip and no run that can poison the next one. NEGATIVE CONTROLS ARE NAMED neg-control-* so a census can COUNT them. A control nobody can find is a control nobody maintains.