dismissRecovery

Manually retire the pending recovery record (user dismissed the banner). Needed for a device whose bootloader can't be re-flashed over BLE at all — e.g. a stock nRF Legacy-DFU bootloader that never answers its control point — where recovery persistently fails and would otherwise nag forever (it only auto-clears on a successful reconnect or re-flash). The record is re-created next time a DFU update is triggered.