nx_symdrop.nx

nx_symdrop.nx -- catch SILENT SYMBOL LOSS in shared sources (seq1407 root fix). THE DEFECT CLASS, witnessed three times: a session lands a source change, verifies it LIVE, and a sibling later writes back a stale WHOLE-FILE copy that erases it. The running binary keeps serving the fix, so every health check stays green -- and the revert only detonates at the NEXT rebuild, silently restoring the old behaviour with NO failing test. My own seq1318 supervisor fix was erased this way 25 minutes after I proved it live (diff against my pre-edit original: ZERO lines = a pure stale-copy write-back, not a competing edit). WHY THIS SHAPE: a fix that must be REMEMBERED at N write sites is not a fix -- and the writes arrive through many doors (nx_fs_write, ssh redirects, treepack unpack, cron rewrites). So bind the check to the one property they all share: after any of them, the FILE'S SYMBOL SET either kept everything it had, or something was removed. Removal is the signal. Additions are normal and ignored. FAIL-CLOSED, and deliberately NOT auto-healing: an unreadable/vanished watched file is itself the defect, so it is reported RED rather than skipped; and nothing here ever rewrites a source. A real removal is legitimised by an explicit `bless`, which makes an intentional deletion a deliberate, recorded act instead of an indistinguishable accident. nx_symdrop check [watchconf] [snapfile] -- compare live symbols vs the snapshot; exit 1 on ANY drop nx_symdrop bless [watchconf] [snapfile] -- accept current symbols as the new baseline nx_symdrop list [watchconf] -- show what is watched and each file's symbol count license_tier: ORIGINAL No hw writes (Rule 26). expect_exit: 0