feat: Update OpenAI runners to implement Runner protocol returning RunnerResult

[jsonbailey]

Summary

• `OpenAIModelRunner` and `OpenAIAgentRunner` now formally inherit from the `Runner` protocol class.
• `OpenAIModelRunner.run()` implements the unified `Runner` protocol; returns `RunnerResult` with `content`, `metrics`, `raw`, and `parsed` fields. Structured output is supported via the `output_type` parameter.
• `OpenAIAgentRunner.run()` updated to return `RunnerResult`; populates `tool_calls` in `LDAIMetrics` from observed openai-agents `ToolCallItem`s.
• Legacy `invoke_model()` and `invoke_structured_model()` removed — the deprecated type definitions (`ModelRunner`, `ModelResponse`, etc.) are kept in `server-ai` for provider CI compatibility until a cleanup PR removes them.

Stacking

Stacked on top of `jb/aic-2388/managed-result` (PR #148).

Test plan

• `make test-openai` — all OpenAI provider tests pass
• `make test` — all tests across server-ai, langchain, and openai packages pass

🤖 Generated with Claude Code

[jsonbailey]

we should add the Runner protocol here vs stating it in the doc below

[jsonbailey]

This should be switched to the Runner protocol.

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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[cursor]

Classes don't inherit Runner protocol despite claiming implementation

Medium Severity

Both OpenAIAgentRunner and OpenAIModelRunner claim in their docstrings to implement the Runner protocol but don't actually inherit from it. This is inconsistent with OpenAIAgentGraphRunner in the same package which explicitly inherits from AgentGraphRunner. Without explicit inheritance, static type checkers cannot verify protocol conformance at definition time, and any future changes to the Runner protocol won't produce errors on these classes. The Runner protocol is imported and available in ldai.providers.

Additional Locations (1)

• packages/ai-providers/server-ai-openai/src/ldai_openai/openai_model_runner.py#L13-L14

 

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[cursor]

Missing deprecated adapters breaks backward compatibility with callers

Medium Severity

The PR description states "Legacy invoke_model() and invoke_structured_model() retained as deprecated adapters that delegate to run() for backward compatibility," but these methods are completely absent from OpenAIModelRunner. The SDK's ManagedModel.invoke() calls self._model_runner.invoke_model() directly without an isinstance check, and Judge.evaluate() calls self._model_runner.invoke_structured_model(). If an OpenAIModelRunner instance is used through either of these existing code paths, it will raise AttributeError at runtime.

 

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