MCP to support stateless_http=True

There is no option to expose MCP tools/resources/prompt with webmvc without sse sessions.
That is something supported in other languages, like fastmcp with python new FastMCP( ... stateless_http=True)

Expected Behavior

Client should be able to send POST like below to get list of tools or execute a tool without sessionId.

curl -X POST http://<MCP_SERVER_HOST>:<PORT>/mcp \
-H "Content-Type: application/json" \
-d '{
    "jsonrpc": "2.0",
    "method": "tools/list",
    "params": {},
    "id": 1
}'

Current Behavior

Client has to establish session with /sse endpoint first or use STDIO.

Context

Not able to expose MCP server easily with Spring AI.

Start by tracing the Spring AI webmvc MCP transport around the /sse and /mcp entry points, comparing them with the STDIO path. Done means a client can POST JSON-RPC requests such as tools/list to /mcp without first establishing a session, while existing session-based behavior remains available.