nx_cachewatch_gate.nx

nx_cachewatch_gate.nx -- THE GATE FOR THE WRITE-CACHE AXIS, 2026-09-03. SUBJECT: the BUILT nx_cachewatch elf, forked against fixture /proc trees this gate writes at runtime. It never reads the real /proc, so it is deterministic on any host and cannot pass or fail because of the box it happens to run on -- which matters especially here, since the real host is currently in the RED state and a gate that read it would be indistinguishable from one hardcoded to say RED. T2 IS THE TOOTH THAT CARRIES THE FILE. Fixtures 1 and 2 have BYTE-IDENTICAL cache_info -- both say `mode=WRITE_BACK` -- and differ ONLY in flashcache_progress. If the organ keyed its verdict on `mode` (the obvious field, and the one a reader reaches for first) both would return the same answer and the detector would have read GREEN through the entire outage that motivated it. T2 requires them to DIFFER, so it can only pass on an organ that discriminates on the right field. T3 IS THE POSITIVE CONTROL. T1/T2/T4/T5 all assert a non-GREEN verdict, and a detector hardwired to alarm passes every one. T3 demands a fully healthy tree return GREEN at exit 0. T6 IS THE COUNTER TRAP, AND IT IS THE DEFECT THAT MOTIVATED THE ORGAN. The fixture plants `dirty_writeback_kb=31543788` -- the real live value -- beside `dirty_blocks=0`. A reader that treats the counter as a level reports tens of GB of stranded dirty data on a degraded unmirrored device: an alarming, actionable, WRONG conclusion that this estate's memory recorded once and this organ's author nearly published again. T6 requires the reported level to stay 0 and the counters to be NAMED as refused. Teeth, in order: T1 the live-host condition (cache flushed+disabled, mirror degraded) -> RED, exit 1. T2 DISCRIMINATOR: identical cache_info, progress differs -> AMBER not RED (mode is not the field). T3 POSITIVE CONTROL: a healthy tree -> GREEN, exit 0. T4 an absent flashcache -> UNOBSERVABLE (3), and specifically NOT GREEN. T5 an unreadable progress file -> UNOBSERVABLE, not a cheerful GREEN. T6 COUNTER TRAP: a huge lifetime counter beside dirty_blocks=0 must not become a level. T7 the degraded count reads [2/1] as degraded and leaves [2/2] and [8/8] alone. T8 ANTI-VACUITY: the four verdicts are four DISTINCT exit codes. MEASURED 8/8 GREEN 2026-09-03, bite-proven killed=1 (source 13321 B and deployed subject 23297 B both restored byte-identical). license_tier: ORIGINAL No hw writes (Rule 26). expect_exit: 0