feat: expand sequential key variables fallback in AIService keys init…

backend/src/services/ai.service.ts

@@ -67,12 +67,19 @@
     if (this.geminiKeys.length === 0) {
       const keysEnv = process.env.GEMINI_API_KEYS;
       if (keysEnv) {
         this.geminiKeys = keysEnv.split(',').map((k) => k.trim()).filter(Boolean);
       } else {
         const key1 = process.env.GEMINI_API_KEY || 'GEMINI_API_KEY_1_PLACEHOLDER';
         const key2 = process.env.GEMINI_API_KEY_2 || 'GEMINI_API_KEY_2_PLACEHOLDER';
         const key3 = process.env.GEMINI_API_KEY_3 || 'GEMINI_API_KEY_3_PLACEHOLDER';
-        this.geminiKeys = [key1, key2, key3];
+        const key4 = process.env.GEMINI_API_KEY_4 || 'GEMINI_API_KEY_4_PLACEHOLDER';
+        const key5 = process.env.GEMINI_API_KEY_5 || 'GEMINI_API_KEY_5_PLACEHOLDER';
+
+        const filtered = [key1, key2, key3, key4, key5].filter(
+          (k) => !k.includes('PLACEHOLDER')
+        );
+
+        this.geminiKeys = filtered.length > 0 ? filtered : [key1];
       }
     }
   }
@@ -1381,7 +1388,7 @@
           });
           const text = response.text;
           if (!text) {
             throw new Error('Gemini returned an empty link categorization response.');
           }
           return text;
         });
@@ -1621,7 +1628,7 @@
 
       const text = response.text;
       if (!text) {
         throw new Error('Gemini returned an empty deadline extraction response.');
       }
       return text;
     });