Expose MCP JSON-RPC protocol metadata via $mcp.getClientInfo

[nmaguiar]

Motivation

• Improve MCP client introspection by returning protocol-level data received via the underlying JSON-RPC transport so callers can inspect the last request/response and transport headers such as mcp-session-id.
• Make it possible to correlate MCP initialize payload/result with captured transport state for debugging and telemetry.

Description

• Added JSON-RPC-level tracking object _mcpInfo (session, lastRequest, lastResponse, lastResponseHeaders) inside $jsonrpc and populate it on each call. (js/openaf.js)
• Exposed a new $jsonrpc.getClientInfo() via getClientInfo that returns the collected _mcpInfo, and added $mcp.getClientInfo() to merge the MCP initialize result into the returned client info. (js/openaf.js)
• Capture mcp-session-id from HTTP response headers and store it in the tracked session info, and record response headers for remote/SSE/notification flows. (js/openaf.js)
• Updated the MCP test server to return a mcp-session-id on initialize and added a test testGetClientInfoIncludesJSONRPCMCPData that asserts getClientInfo() contains lastRequest, lastResponse envelope, captured session.mcpSessionId, and the initialize result. (tests/autoTestAll.MCP.js)

Testing

• Added/updated tests in tests/autoTestAll.MCP.js, including testGetClientInfoIncludesJSONRPCMCPData which validates JSON-RPC/MCP metadata fields and mcp-session-id capture; the test file was modified as part of this change.
• Attempted to run the test orchestrator with cd tests && ../openaf --ojob autoTestAll.MCP.yaml, which failed because the openaf CLI is not available in this environment.
• Attempted to run with the built JAR via cd tests && java -jar ../openaf.jar --ojob autoTestAll.MCP.yaml, which failed because openaf.jar is not present in this environment.