Fix Redis transport refactoring with control message system

- Fix timing issue by awaiting startServerListeningToRedis
- Add request-id based response channel routing
- Implement control message system for proper server shutdown
- Add comprehensive integration tests
- Ensure response subscription is established before message sending
- Fix MCP server cleanup integration to prevent async hanging

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/handlers/shttp.ts

@@ -44,7 +44,7 @@ export async function handleStreamableHTTP(req: Request, res: Response) {
       const server = createMcpServer();
       console.log('Created MCP server instance');
       
-      startServerListeningToRedis(server.server, sessionId)
+      await startServerListeningToRedis(server, sessionId)
       console.log('Started server listening to Redis for session:', sessionId);
       
       ({ shttpTransport, cleanup } = await getFirstShttpTransport(sessionId));