CHW-4943 CLIDeviceCodeExpired

device code not found or expired; restart the `chainsaw auth login` flow

Default message: device code not found or expired; restart the chainsaw auth login flow
HTTP status: 404 (client)

Problem. The device_code was valid-shape but the grant has been garbage-collected. Cause. Grant TTL elapsed before the user approved, or the code never existed. Fix. Restart the chainsaw auth login flow. Surfaced as 404 to mirror the legacy “status: expired” body semantics — clients treat “not found” and “expired” identically. HTTP 404.