refactor(OpenCode TLS): 共用 httpsAgent 建立邏輯

app/llm.js

@@ -1,6 +1,5 @@
 import axios from 'axios';
-import https from 'https';
-import { getLLMConfig, shouldSkipOpenCodeTLSVerify } from './config.js';
+import { getLLMConfig, getOpenCodeHttpsAgent } from './config.js';
 import { line, error } from './log.js';
 
 function isOpenAIGpt55(provider, model) {
@@ -50,7 +49,7 @@ function applyOpenCodeAuth(headers) {
 function opencodeAxiosOptions(headers) {
   return {
     headers,
-    httpsAgent: shouldSkipOpenCodeTLSVerify() ? new https.Agent({ rejectUnauthorized: false }) : undefined,
+    httpsAgent: getOpenCodeHttpsAgent(),
   };
 }