1962938fa5
- Added `onPayload` callback option to intercept and transform provider request payloads before transmission across agent and AI packages. - Added structured text signature metadata with phase information to OpenAI and Azure OpenAI providers for enhanced response tracking. - Added `before_provider_request` extension event to coding-agent for chaining payload transformations across multiple handlers. - Improved error messages in `response.failed` events with detailed error codes, messages, and incomplete reasons from provider responses.