write/edit failures with FS_STALE_VERSION or FS_NOT_OBSERVED now reach the
model with the correct recovery instruction appended (re-read / read, then
retry) while preserving the structured code and chaining the cause. The
edit-intent waterfall sits inside the same try, so the policy's
FS_NOT_OBSERVED refusal is remediated too. Re-recorded the fs-policy-reject
keyless snapshot and the bilingual README pairs.
