List tenant channels

Use first to discover saved channel.id, provider/type, active/respondEnabled and saved readiness/version fields for the connected business. Use the stored id for channel tools; provider phone/page/WABA IDs are separate identifiers. Read get_channel for detail, get_whatsapp_channel_health for live Meta checks, and get_channel_connection_options before adding a channel. Listing does not create a webchat channel, prove OAuth readiness or message delivery. Requires channels:read.