Response field message_count removed

What changed

Reads of this field return undefined, and the failure surfaces wherever that value is used rather than at the call.

Affects InboxThread reachable from 2 operations.

Who is affected

Code that reads Resend's InboxThread objects, used by 2 Resend operations.

Before and after

Code that breaks

// response.message_count is now undefined
const message_count = response.message_count;

Based on Resend’s published API specification. How severity is decided.