nx_conductor_notes_migration_gate.nx

nx_conductor_notes_migration_gate.nx -- WMS-R0b DELIVERABLE B referee. Proves the MIGRATED conductor-notes record write (multi-_fp/_fn sequence -> single atomic locked fa_appendz) produces ZERO torn lines under concurrency, AND proves the detector can actually SEE tearing via the mandatory in-gate NEGATIVE CONTROL: the OLD _fp/_fn multi-write path, which MUST tear (bad_torn > 0) -- if it doesn't, the test is worthless => RED (no false green). GOOD lane (the migration): N workers fork concurrently, each emits NRECS NOTES records the NEW way -- assemble the whole "NOTES epoch=<e> weakest_arc=<arc> call=...:triage ... verdict=DRILL-CALLED" line into one buffer + ONE fa_appendz (the exact cn_emit_red shape). Expect ZERO torn lines and ALL N*NRECS lines present. BAD lane (NEGATIVE CONTROL): same concurrency, but each record emitted the ORIGINAL way -- a SEQUENCE of separate _fp/_fn sys_write() calls to one O_APPEND fd ("NOTES epoch=" then the number then " weakest_arc=" ...). Concurrent workers interleave between those writes -> torn lines MUST appear. TAMPER: an oversized record (rec_len+1 > cap) must be REJECTED with -2. A line is WELL-FORMED iff it starts "NOTES epoch=" AND its last 12 bytes before the '\n' are "DRILL-CALLED" AND it contains exactly one "NOTES epoch=" head and exactly one "DRILL-CALLED" tail. Any interleaving breaks one of those -> torn. Output: rows -> stdout + knowledge/status/conductor_notes_migration_gate.log, then a verdict line. Exit 0 on GREEN, 1 on RED. Sovereign: only nx_syscalls + nx_framed_append. license_tier: ORIGINAL