Main removed the live-path runtime FTS rebuild (18ac3c4fb6) and #99652
narrowed the corruption classifier, after the salvaged PR #89364 branched.
Update its tests to assert the current contract: no fail-open detach on a
replaced file (fts_enabled stays True, no stale marker), fail-open (not
rebuild) for genuine same-file FTS corruption, and FTS-provenance errors
for the guard probe since generic malformed no longer reaches fail-open.
Detect same-inode cp via a generation stamp, halt FTS repair, and divert
unwritten transcripts to sessions/<id>.jsonl plus the gateway pending spool.
Co-authored-by: Cursor <cursoragent@cursor.com>
Teknium