fix(OpenCode 呼叫): 降低並行請求並重試暫時性錯誤

app/llm.js

@@ -32,6 +32,10 @@ function opencodeAxiosOptions(headers) {
   };
 }
 
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
 /**
  * 從 OpenCode 訊息回應中抽取並串接所有文字片段。
  *
@@ -66,6 +70,11 @@ function formatOpenCodeError(e) {
   return response ? `${statusText}: ${response}` : statusText;
 }
 
+function isTransientOpenCodeError(e) {
+  const status = e.response?.status;
+  return status === 500 || status === 502 || status === 503 || status === 504 || status === 429;
+}
+
 /**
  * 對 OpenCode server 執行一次完整對話：建立 session 後送出訊息並回傳結果。
  *
@@ -104,6 +113,23 @@ async function chatOpenCode(baseURL, model, systemPrompt, userContent, headers)
   return { content: extractOpenCodeContent(resp.data), data: resp.data };
 }
 
+async function chatOpenCodeWithRetry(baseURL, model, systemPrompt, userContent, headers) {
+  const maxAttempts = Number(process.env.OPENCODE_RETRY_ATTEMPTS || 3);
+  let lastError;
+  for (let attempt = 1; attempt <= maxAttempts; attempt++) {
+    try {
+      return await chatOpenCode(baseURL, model, systemPrompt, userContent, headers);
+    } catch (e) {
+      lastError = e;
+      if (!isTransientOpenCodeError(e) || attempt === maxAttempts) throw e;
+      const delay = Math.min(1000 * 2 ** (attempt - 1), 8000);
+      line(`[LLM] OpenCode 暫時性錯誤，${delay}ms 後重試 (${attempt}/${maxAttempts}): ${formatOpenCodeError(e)}`);
+      await sleep(delay);
+    }
+  }
+  throw lastError;
+}
+
 /**
  * 對 OpenCode server 送出一次對話請求並回傳模型純文字回應。
  *
@@ -125,7 +151,7 @@ export async function chat(systemPrompt, userContent) {
   const headers = { 'Content-Type': 'application/json' };
 
   try {
-    const { content, data } = await chatOpenCode(baseURL, model, systemPrompt, userContent, headers);
+    const { content, data } = await chatOpenCodeWithRetry(baseURL, model, systemPrompt, userContent, headers);
     recordUsage(data);
     return content;
   } catch (e) {