fix: restrict stream route handling to GET requests

Made-with: Cursor

Author: TryKosm

server/index.ts

@@ -2,7 +2,7 @@ import http from "node:http";
 import { toSseChunks } from "./stream.js";
 
 const server = http.createServer((req, res) => {
-  if (req.url === "/stream") {
+  if (req.url === "/stream" && req.method === "GET") {
     res.writeHead(200, {
       "Content-Type": "text/event-stream",
       "Cache-Control": "no-cache",