Implements missing streaming events from OpenAI Responses API spec:
- reasoning text/summary events for o1/o3 models,
- refusal events for safety moderation
- annotation events for citations,
- and file search streaming events.
Added optional reasoning_content field to chat completion chunks to
support non-standard provider extensions.
**NOTE:** OpenAI does _not_ fill reasoning_content when users use the
chat_completion APIs. This means there is no way for us to implement
Responses (with reasoning) by using OpenAI chat completions! We'd need
to transparently punt to OpenAI's responses endpoints if we wish to do
that. For others though (vLLM, etc.) we can use it.
## Test Plan
File search streaming test passes:
```
./scripts/integration-tests.sh --stack-config server:ci-tests \
--suite responses --setup gpt --inference-mode replay --pattern test_response_file_search_streaming_events
```
Need more complex setup and validation for reasoning tests (need a vLLM
powered OSS model maybe gpt-oss which can return reasoning_content). I
will do that in a followup PR.
Implementats usage accumulation to StreamingResponseOrchestrator.
The most important part was to pass `stream_options = { "include_usage":
true }` to the chat_completion call. This means I will have to record
all responses tests again because request hash will change :)
Test changes:
- Add usage assertions to streaming and non-streaming tests
- Update test recordings with actual usage data from OpenAI
Renames `inference_recorder.py` to `api_recorder.py` and extends it to
support recording/replaying tool invocations in addition to inference
calls.
This allows us to record web-search, etc. tool calls and thereafter
apply recordings for `tests/integration/responses`
## Test Plan
```
export OPENAI_API_KEY=...
export TAVILY_SEARCH_API_KEY=...
./scripts/integration-tests.sh --stack-config ci-tests \
--suite responses --inference-mode record-if-missing
```