- Add sendMessage() to outbound.ts with opt-in check, find/create conversation, queued→sent/failed transitions
- Add unit tests for success, opt-out suppression, missing tenant phone
- Add uuid and @types/uuid to package.json dependencies
- sms.ts unchanged (already Telnyx transport only on dev)
PR for GRO-1016 (replacement for #379)
Closes GRO-984
Co-Authored-By: Paperclip <noreply@paperclip.ing>