Adds GET /api/auth/me/devices to list a user's paired devices
(label, lastSeen, channels, isCurrent marker) plus matching DELETE
routes at /api/auth/me/devices/[id] and /api/devices/[id]. Revoke
cascades: every refresh token bound to the device is killed alongside
its paired access tokens, then the device row is deleted.
Cross-user attempts return 404 (no enumeration leak). The duplicated
/api/devices/[id] endpoint is the native-friendly URL the iOS client
calls on APNs token rotation, mirroring the W3 open question.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>