- Extracted OpenAI Responses API stream processing logic into shared module with 424 lines of reusable utilities.
- Consolidated text signature encoding, tool call normalization, and message conversion functions into openai-responses-shared module.
- Refactored openai-responses.ts and azure-openai-responses.ts to delegate stream processing to shared processResponsesStream() helper.
- Removed 473 lines of duplicated stream event handling and utility functions across OpenAI provider implementations.