feat: support multiple API keys for LLM providers, allowing automatic key rotation on failure

app/llm.js

@@ -5,23 +5,31 @@ import { getLLMConfig } from './config.js';
 const httpsAgent = new https.Agent({ rejectUnauthorized: false });
 
 export async function chat(systemPrompt, userContent) {
-  const { provider, apiKey, baseURL, model } = getLLMConfig();
+  const { provider, apiKeys, baseURL, model } = getLLMConfig();
   if (!provider) throw new Error('未設定任何 LLM API Key');
 
   console.log(`  [LLM] provider=${provider} model=${model}`);
 
-  const headers = {
-    'Content-Type': 'application/json',
-    'Authorization': `Bearer ${apiKey}`,
-  };
+  const headers = { 'Content-Type': 'application/json' };
   if (provider === 'claude') headers['anthropic-version'] = '2023-06-01';
 
-  const resp = await axios.post(
-    `${baseURL.replace(/\/$/, '')}/chat/completions`,
-    { model, messages: [{ role: 'system', content: systemPrompt }, { role: 'user', content: userContent }], temperature: 0.2 },
-    { headers, timeout: 120000, httpsAgent }
-  );
-  return resp.data.choices[0].message.content;
+  let lastError;
+  for (let i = 0; i < apiKeys.length; i++) {
+    headers['Authorization'] = `Bearer ${apiKeys[i]}`;
+    try {
+      const resp = await axios.post(
+        `${baseURL.replace(/\/$/, '')}/chat/completions`,
+        { model, messages: [{ role: 'system', content: systemPrompt }, { role: 'user', content: userContent }], temperature: 0.2 },
+        { headers, timeout: 120000, httpsAgent }
+      );
+      return resp.data.choices[0].message.content;
+    } catch (e) {
+      lastError = e;
+      console.log(`  [LLM] key[${i + 1}/${apiKeys.length}] 失敗: ${e.message}`);
+    }
+  }
+  console.error('  [LLM] 所有 API Key 均失敗，終止流程');
+  process.exit(1);
 }
 
 export async function chatJSON(systemPrompt, userContent) {