fix(ai): replay native hosted tool items - #45038

Summary

• replay completed provider-hosted tool items in their original native Responses shape when continuing with the same provider and store: false
• preserve existing portable message fallback when switching providers, when item IDs do not match provider metadata, or when the result is an image/error rather than a replayable JSON item
• retain stored-response item references and existing hosted image generation behavior
• cover OpenAI native replay, OpenAI-to-xAI provider switches, mismatched item IDs, and xAI-native hosted tools

Before and after

A completed hosted search produces the provider-native item:

{ "type": "web_search_call", "id": "ws_1", "status": "completed" }

Before: A subsequent stateless request rewrote that item as a synthetic user message:

{ "role": "user", "content": [{ "type": "input_text", "text": "{\"type\":\"web_search_call\",\"id\":\"ws_1\",\"status\":\"completed\"}" }] }

After: Continuing with the same provider preserves the original item, matching Codex history replay:

{ "type": "web_search_call", "id": "ws_1", "status": "completed" }

If the next model belongs to another provider, the original item is not replayed as foreign provider state; its portable text representation remains available instead. Hosted generated images likewise continue to replay as input images.

Verification

• bun test test/partial-json.test.ts test/tool-stream.test.ts test/provider/openai-responses.test.ts test/provider/openai-compatible-responses.test.ts test/provider/openai-responses-images.recorded.test.ts test/provider/openai-responses-websocket.recorded.test.ts test/provider/openai-chat.test.ts test/provider/anthropic-messages.test.ts test/provider/bedrock-converse.test.ts test/provider/xai-responses.test.ts test/response.test.ts test/tool-runtime.test.ts --timeout 30000 --only-failures (367 passing)
• RECORDED_PREFIX=openai-responses bun test test/provider/golden.recorded.test.ts --timeout 30000 --only-failures
• bun typecheck from packages/ai
• bunx prettier --check packages/ai/src/protocols/open-responses.ts packages/ai/test/provider/openai-responses.test.ts packages/ai/test/provider/xai-responses.test.ts