fix: address security review findings, implement real cache clearing, and fix lifecycle promises

shared/modules/economy/lootdrop.service.ts

@@ -163,6 +163,11 @@ class LootdropService {
             return { success: false, error: "An error occurred while processing the reward." };
         }
     }
+    public async clearCaches() {
+        this.channelActivity.clear();
+        this.channelCooldowns.clear();
+        console.log("[LootdropService] Caches cleared via administrative action.");
+    }
 }
 
 export const lootdropService = new LootdropService();