添加Health健康检查端点

server/cache.js

@@ -63,6 +63,17 @@ const cache = {
     } catch (e) {
       // ignore
     }
+  },
+
+  async checkHealth() {
+    if (!redis) return { status: 'down', error: 'Valkey client not initialized' };
+    try {
+      const result = await redis.ping();
+      if (result === 'PONG') return { status: 'up' };
+      return { status: 'down', error: 'Invalid ping response' };
+    } catch (e) {
+      return { status: 'down', error: e.message };
+    }
   }
 };