Document and test raw provider error-code mappings into the SDK `SmsErrorCode` taxonomy. Goal: make retry/fallback behavior predictable across vendors and easier to maintain. Start with Twilio/Telnyx/Plivo/SNS tables plus adapter tests.
Document and test raw provider error-code mappings into the SDK
SmsErrorCodetaxonomy.Goal: make retry/fallback behavior predictable across vendors and easier to maintain. Start with Twilio/Telnyx/Plivo/SNS tables plus adapter tests.