feat: add health check command and tracking

src/lib/handlers/CommandHandler.ts

@@ -26,6 +26,7 @@ export class CommandHandler {
 
         try {
             await command.execute(interaction);
+            AuroraClient.lastCommandTimestamp = Date.now();
         } catch (error) {
             logger.error(String(error));
             const errorEmbed = createErrorEmbed('There was an error while executing this command!');