Check account health

Returns detailed health info for a specific account including token status, permissions, and recommendations.

For WhatsApp accounts the response also includes platformConnection, a live probe of the Meta link behind the channel (the same read as GET /v1/whatsapp/number-info). The OAuth token can be perfectly valid while Meta refuses to serve the phone-number object (for example after a phone-side coexistence disconnect), so tokenStatus alone is not a liveness signal for WhatsApp. When the Meta link is dead, platformConnection.status is disconnected and the overall status is error.