Remote invocations return no data when running `azd ai agent invoke`

Description:
When testing Scenario 3: LangGraph Toolbox (Responses), remote invocations do not return response data when running azd ai agent invoke --protocol invocations '{"input": "What can you help me with?"}' or azd ai agent invoke --protocol invocations '{"input": "Give me a short code example."}'. The command starts successfully and prints the invocation metadata (agent, session, conversation, and trace ID), but no actual response is returned.

Running azd ai agent monitor --tail 20 shows that the request is received and processed by the service, and the logs contain backend errors such as openai.NotFoundError / DeploymentNotFound.

Steps to Reproduce:

1. mkdir github-copilot-invocations and cd github-copilot-invocations
2. Run azd ai agent init --manifest "https://github.com/microsoft-foundry/foundry-samples/blob/main/samples/python/hosted-agents/bring-your-own/invocations/github-copilot/agent.manifest.yaml" and select location northcentralus.
3. Run azd up.
4. Run azd ai agent invoke --protocol invocations '{"input": "What can you help me with?"}' or azd ai agent invoke --protocol invocations '{"input": "Give me a short code example."}'.
5. Run azd ai agent monitor --tail 20.

Environment:

• Azd version: azd version 1.25.3-daily.6367899 (commit 5415d38ec116421c280491764d5ff559e6cd0f7f) (daily).
• AI Agent Extension version: 0.1.34-preview
• Manifest URL: https://github.com/microsoft-foundry/foundry-samples/blob/main/samples/python/hosted-agents/bring-your-own/responses/langgraph-toolbox/agent.manifest.yaml
• OS: Windows
• Location: northcentralus.

Expected Behavior:
Remote invoke should succeed.

@JeffreyCA and @RickWinter for notification.