StreamableHTTP Client integration tests

Create integration tests for Client with StreamableHTTP transport:

1. Roots

• Capabilities https://modelcontextprotocol.io/specification/draft/client/roots#capabilities
• Listing Roots https://modelcontextprotocol.io/specification/draft/client/roots#listing-roots
  • Bad request
  • Security - Allow
  • Security - Deny
• Root list changes https://modelcontextprotocol.io/specification/draft/client/roots#root-list-changes

2. Sampling

• Capabilities
  • Creating Messages - Text https://modelcontextprotocol.io/specification/draft/client/sampling#creating-messages
  • Creating Messages - Image
  • Creating Messages - Audio

3. Elicitation

• Capabilities
• Creating Elicitation Requests - Text https://modelcontextprotocol.io/specification/draft/client/elicitation#creating-elicitation-requests
• Creating Elicitation Requests - Structured Data https://modelcontextprotocol.io/specification/draft/client/elicitation#structured-data-request
  • Supported Schema Types - String
  • Supported Schema Types - Number
  • Supported Schema Types - Enum
  • Reject Response
  • Cancel Reponse

Start at the Client integration-test entry points for the StreamableHTTP transport and compare the unchecked Roots, Sampling, and Elicitation cases with the linked MCP specification sections. Add coverage for each listed scenario, including bad requests, security decisions, audio, structured data, rejection, and cancellation, with all checklist items passing.