Patch Changes

• ea91d7d: ctx7 login now always uses the device-code flow. The localhost-callback path is removed — every install (laptop, SSH, Codespace, Docker, CI) goes through the same boxed prompt and verification page. Drops the --device flag (it was the opt-in for what's now the default). Older CLI versions (≤ 0.5.0) continue to work against the unchanged auth endpoints, so pinned installs are unaffected.