Track execution state per item and retry through a fresh preview
Runs now carry an execution_status on every item plus a preflight summary and progress rollup, so a failed or uncertain write is visible on the row that caused it instead of only in the result log. Items that already match the live org can be recorded as verified without writing anything, and conflicts block execution before the lock is taken. A failed run can be retried, but only by building a new live preview so the retry revalidates instead of repeating the request blindly; uncertain writes still have to be reconciled first. The plan contract now documents which categories the direct Zoho executor covers.