List administrable Business Central connections

Default off and outside the MCP OAuth profile. Requires a separate OWNER or ADMIN organization API key with org:integrations:write, org:* or * scope. Accounts must have supplied a fresh signed v2 or v3 purchaser tenant; the customer cannot enter or rebind tenant authority. Administrators authorize an environment/company and dedicated read-only BC application separately. Credentials are encrypted with an explicitly configured integration custody key and never returned. Verification performs bounded reads only; no ERP write is available.