JS Anthropic AI SDK - gen_ai.request.messages attribute incomplete

[linear]

    Error: Fixture validation failed:
    llm_call (gen_ai.messages):
       gen_ai.request.messages: mismatch (
         expected: {"type":"json_array","min_length":2,"items_have":["role","content"]},
         got: "[{\"role\":\"user\",\"content\":\"What is 69 + 96?\"}]"
       )

  "dependencies": {
    "@anthropic-ai/sdk": "0.68.0",
    "@sentry/node": "10.26.0",

The issue is that it's not adding the system prompt to the gen_ai.messages span.

[linear]

JS-1223