Enable full HTTP elicitation support after SDK streaming API is available

[olaservo]

Summary

The simulate-research-query tool in the Everything Server currently implements graceful degradation for elicitation on HTTP transport. When running over HTTP, elicitation attempts fail and the task uses a default interpretation instead of prompting the user.

This is because the SDK's sendRequest doesn't work for elicitation over HTTP - the connection is closed after the initial CreateTaskResult response.

Background

The SDK's streaming elicitation API (elicitInputStream) enables elicitation over HTTP by creating a new SSE stream. Once this is available in a released SDK version, we can upgrade to full HTTP elicitation support.

Changes needed

1. Update @modelcontextprotocol/sdk dependency to version with streaming elicitation
2. Replace try-catch sendRequest pattern with streaming API in simulate-research-query.ts
3. Follow spec-compliant pattern:
   • Set input_required status before elicitation (spec SHOULD)
   • Use streaming elicitation (works over HTTP)
   • Transition back to working after receiving input (spec SHOULD)

Current behavior

Transport	Elicitation	Task Completion
STDIO	✅ Works	✅ Works
HTTP	❌ Graceful degradation	✅ Works (uses default)

Target behavior

Transport	Elicitation	Task Completion
STDIO	✅ Works	✅ Works
HTTP	✅ Works (via streaming)	✅ Works