f7c60945d0
devices rows no longer carry public_key for crypto purposes. The whole
per-device key API surface (provisionNewDevice, loadDevicePrivateKey,
saveDevicePrivateKey, forgetDevicePrivateKey, restoreDeviceFromServerRecord)
is removed; registerDevice now records {name, platform} only. SQL drops the
NOT NULL on devices.public_key so future telemetry rows can omit it.
Note: SQL not applied locally - push via pnpm prod:migrate when ready.