A full file_write that shrinks a non-trivial existing file (>=30 non-blank
lines) by >60% into a stub with literal `...` placeholders is almost always
the model rewriting a file from memory instead of editing it — the incident
that silently broke SessionRoutes.kt (273->28 lines) in run f11afb08. Reject it
(recoverable) and steer to file_edit. Requires BOTH the hard shrink AND elision
markers, so dead-code refactors and new-file scaffolds pass untouched. Runs
before the write regardless of approval tier, so the auto-driver can't wave it
through.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
kami
0e1095e9ba