Fix: Add type guard for possibly undefined mongoose connection db

src/lib/actions/agents.ts

@@ -20,6 +20,9 @@ export async function updateAgent(agentId: string, label: string) {
       await mongoose.connect(MONGODB_URI, { serverSelectionTimeoutMS: 5000 });
     }
     const db = mongoose.connection.db;
+    if (!db) {
+      throw new Error("Database tidak tersedia.");
+    }
     
     // Check if agent exists in agent_registry
     const agent = await db.collection('agent_registry').findOne({ $or: [{ uuid: agentId }, { serial: agentId }] });
@@ -54,6 +57,9 @@ export async function deleteAgent(agentId: string) {
       await mongoose.connect(MONGODB_URI, { serverSelectionTimeoutMS: 5000 });
     }
     const db = mongoose.connection.db;
+    if (!db) {
+      throw new Error("Database tidak tersedia.");
+    }
     
     // Check if agent exists in agent_registry
     const agent = await db.collection('agent_registry').findOne({ $or: [{ uuid: agentId }, { serial: agentId }] });
@@ -104,6 +110,10 @@ export async function getAgents(clientSiteUuid?: string): Promise<Agent[]> {
         return []; // Do not throw to avoid Next.js Server Component crash
       }
       const db = mongoose.connection.db;
+      if (!db) {
+        console.error("[getAgents Action] Database is undefined.");
+        return [];
+      }
 
       return await fetchAgentsFromMongo(db, user, SITE_UUID);
     }