[kinqsradio]

Summary

• DeviceClient::check_invite(code) wraps POST /v1/invites/check ({invite} -> 204): Ok when the code can start a sign-up, InviteInvalid for an unknown, used or expired one (the server gives one answer for all), RateLimited after too many wrong tries; a server that asks for no invites says yes. It spends nothing and sends the code as typed. No InviteRequired variant exists, so the existing InviteInvalid is used.
• Scripted-transport tests (fake engine route; 429 and a dead network) and a real-server test in invite mode (good code however typed, unknown, empty, expired, used).
• docs/device-client.md: one paragraph in the sign-up section.
• Re-exports from orbyn-engineering through orbyn-device-client: ZONE_SETTINGS, PERSON_SETTINGS, PERSON_RECORD_ID, Settings, and the types its methods expose (SettingsError, Rule, Accepted, Rejected), so the app does not spell the names by hand. New dependency edge orbyn-device-client -> orbyn-engineering, approved by the lead, added to ALLOWED in scripts/check_structure.py; orbyn-engineering does not depend on the device client (no cycle). Tested by tests/reexports.rs; single_crate and the D6 scan stay green. Noted in docs/device-client.md.

Testing

• Full gate with Postgres: fmt, clippy, structure, wasm32, workspace tests (991 pass).
• Mutation checks: 3 mutations (always Ok, wrong path, altered code), all killed.
• Not tested: the CI clippy toolchain (local only).

Co-authors

none

AI usage

• Written by hand, with no AI
• Harness and version: Claude Code 2.1.317
• Models: claude-sonnet-5-5 (all)
• Effort: medium
• Human role: set scope (Engineering 2's request)
• Sources: none

Checklist

• Works on Windows, macOS and Linux
• docs/architecture.md with any rule change; generated wire types with any contract change
• No copied source, secrets, credentials or personal data; no AI attribution in commits, title or branch