refactor: 统一端口配置，通过 IPC 获取而非硬编码

src/modules/opencode/OpenCodePage.tsx

@@ -1,16 +1,20 @@
 import React, { useEffect, useState } from 'react'
 
-const XCOPENCODEWEB_PORT = 3002
-
 export const OpenCodePage: React.FC = () => {
   const [isRunning, setIsRunning] = useState(false)
   const [error, setError] = useState<string | null>(null)
+  const [port, setPort] = useState<number>(3002)
 
   useEffect(() => {
     let mounted = true
 
-    const startService = async () => {
+    const init = async () => {
       try {
+        const portResult = await window.electronAPI.xcOpenCodeWebGetPort()
+        if (mounted) {
+          setPort(portResult.port)
+        }
+
         const result = await window.electronAPI.xcOpenCodeWebStart()
         if (mounted) {
           if (result.success) {
@@ -27,7 +31,7 @@ export const OpenCodePage: React.FC = () => {
       }
     }
 
-    startService()
+    init()
 
     return () => {
       mounted = false
@@ -51,7 +55,7 @@ export const OpenCodePage: React.FC = () => {
       </div>
       {isRunning && (
         <iframe
-          src={`http://localhost:${XCOPENCODEWEB_PORT}`}
+          src={`http://localhost:${port}`}
           className="flex-1 w-full border-0"
           title="XCOpenCodeWeb"
         />