revert: back to stateful /mcp

server.mjs

@@ -594,8 +594,10 @@ function errResp(text) {
 // Traditional SSE transport sessions (for Figma / older MCP clients)
 const sseSessions = new Map();
 
-// Stateless Streamable HTTP transport (compatible with native MCP clients)
-const mcpTransport = new StreamableHTTPServerTransport({ sessionIdGenerator: undefined });
+// Stateful Streamable HTTP transport (for Cursor / native MCP clients)
+const mcpTransport = new StreamableHTTPServerTransport({
+  sessionIdGenerator: () => crypto.randomUUID(),
+});
 await mcpServer.connect(mcpTransport);
 
 const httpServer = http.createServer(async (req, res) => {