Fix TCP socket API and skip HTTP port testing in network diagnostic

- Import connect from cloudflare:sockets instead of globalThis
- Fix socket.opened / readable / writable API usage
- Skip TCP test for HTTP ports (80/443) since fetch HEAD already covers
  them; only test user-specified non-HTTP ports (e.g. SSH, DB)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/agents/troubleshoot-agent.ts

@@ -163,7 +163,7 @@ export class TroubleshootAgent extends BaseAgent<TroubleshootSession> {
               ports: {
                 type: 'array',
                 items: { type: 'number' },
-                description: '추가로 테스트할 TCP 포트 목록 (기본: 80, 443)',
+                description: '추가로 TCP 연결 테스트할 포트 목록 (예: [22, 3306, 5432]). HTTP 포트(80/443)는 HTTP 체크로 커버되므로 제외됨',
               },
             },
             required: ['domain'],

src/services/network-diagnostic.ts

@@ -8,6 +8,7 @@
  * - TCP 포트 연결 테스트
  */
 
+import { connect } from 'cloudflare:sockets';
 import type { NetworkDiagnosticReport, DnsResolverResult, IspDnsBlockResult, HttpCheckResult, TcpCheckResult } from '../types';
 import { createLogger } from '../utils/logger';
 
@@ -223,20 +224,17 @@ function parseDnsResponse(raw: Uint8Array): string[] {
  * TCP 소켓으로 DNS 서버에 질의
  */
 async function queryDnsTcp(serverIp: string, query: Uint8Array): Promise<string[]> {
-  const socket = (globalThis as unknown as {
+  const socket = connect({ hostname: serverIp, port: 53 });
-    connect: (opts: { hostname: string; port: number }) => {
-      opened: Promise<{ readable: ReadableStream; writable: WritableStream }>;
-      close: () => void;
-    };
-  }).connect({ hostname: serverIp, port: 53 });
 
-  const { readable, writable } = await socket.opened;
+  // Wait for connection to establish
+  await socket.opened;
 
-  const writer = writable.getWriter();
+  // readable/writable are on the socket object directly
+  const writer = socket.writable.getWriter();
   await writer.write(query);
   writer.releaseLock();
 
-  const reader = readable.getReader();
+  const reader = socket.readable.getReader();
   const chunks: Uint8Array[] = [];
   let totalLength = 0;
 
@@ -256,7 +254,7 @@ async function queryDnsTcp(serverIp: string, query: Uint8Array): Promise<string[
     }
   } finally {
     reader.releaseLock();
-    socket.close();
+    await socket.close();
   }
 
   // Combine chunks
@@ -357,15 +355,21 @@ async function checkHttp(domain: string): Promise<HttpCheckResult[]> {
 // TCP Port Test (connect API — ping substitute)
 // ============================================================================
 
-const DEFAULT_PORTS = [80, 443];
+// Cloudflare Workers의 connect()는 HTTP 포트(80/443)에 직접 연결 불가
+// (프록시 차단됨). HTTP 체크로 커버되므로 TCP는 사용자 지정 포트만 테스트.
+const HTTP_PORTS = new Set([80, 443, 8080, 8443]);
 
 async function checkTcpPorts(domain: string, ports?: number[]): Promise<TcpCheckResult[]> {
+  // 사용자가 포트를 지정하지 않으면 TCP 테스트 스킵 (HTTP 체크로 충분)
+  const filteredPorts = (ports || []).filter((p) => !HTTP_PORTS.has(p));
+  if (filteredPorts.length === 0) return [];
+
   // Resolve domain first to get IP for connect()
   const dohResult = await resolveDoh(domain);
   const ip = dohResult[0]?.records[0]?.value;
 
   if (!ip) {
-    return (ports || DEFAULT_PORTS).map((port) => ({
+    return filteredPorts.map((port) => ({
       host: domain,
       port,
       connected: false,
@@ -375,22 +379,17 @@ async function checkTcpPorts(domain: string, ports?: number[]): Promise<TcpCheck
   }
 
   return Promise.all(
-    (ports || DEFAULT_PORTS).map(async (port) => {
+    filteredPorts.map(async (port) => {
       const start = Date.now();
       try {
         const timeoutPromise = new Promise<never>((_, reject) =>
           setTimeout(() => reject(new Error('timeout')), CHECK_TIMEOUT_MS)
         );
 
-        const socket = (globalThis as unknown as {
+        const socket = connect({ hostname: ip, port });
-          connect: (opts: { hostname: string; port: number }) => {
-            opened: Promise<unknown>;
-            close: () => void;
-          };
-        }).connect({ hostname: ip, port });
 
         await Promise.race([socket.opened, timeoutPromise]);
-        socket.close();
+        await socket.close();
 
         return {
           host: domain,