Update startSSEServer.ts with /health endpoint

Author: timudmcqueen

src/startSSEServer.ts

@@ -54,6 +54,11 @@ export const startSSEServer = async <T extends ServerLike>({
       return;
     }
 
+    if (req.method === "GET" && req.url === "/health") {
+      res.writeHead(200, { "Content-Type": "text/plain" }).end("OK");
+      return;
+    }
+    
     if (req.method === "GET" && req.url === `/ping`) {
       res.writeHead(200).end("pong");