Skip deployment of revisions already contained in the live checkout.

docs/work/capy-deploy-automation.md

@@ -91,3 +91,4 @@ The updater does not replace its own installed assets. Install later reviewed up
 - 2026-09-12: The updater deployed `639d472` in 124 seconds. It passed all six compiler/runtime gates and returned service result `success` with exit status 0. Its deployment-run scaling ratios were 0.990 and 2.005, with large medians 15.621 ms and 64.071 ms. Bearer is active. The public `/info/` request returned HTTP 200.
 - 2026-09-12: A second updater invocation logged `already at 639d4720d3bf52bad3bb6bafc9d6df51360b8996, nothing to do` and returned success.
 - 2026-09-12: All 12 files in the three original rollback points retained their hashes. The new deployment added a fourth complete point at `/var/backups/capy-bearer/20260912T135543`, containing the prior `7e571ed` artifacts. The exact installed retention command reduced seven scratch points to the newest five without altering their contents. No real rollback point was deleted.
+- 2026-09-29: `git merge --ff-only` exits 0 for an ancestor target. An origin behind the live checkout made the updater install older binaries. The updater now stops when the live checkout contains the remote head.