refactor: move troubleshoot-agent to agents directory

- Move troubleshoot-agent.ts to src/agents/
- Update import paths in dependent files

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/tools/troubleshoot-tool.ts

@@ -35,7 +35,7 @@ export async function executeManageTroubleshoot(
     return '🚫 트러블슈팅 기능을 사용할 수 없습니다.';
   }
 
-  const { getTroubleshootSession, saveTroubleshootSession, deleteTroubleshootSession } = await import('../troubleshoot-agent');
+  const { getTroubleshootSession, saveTroubleshootSession, deleteTroubleshootSession } = await import('../agents/troubleshoot-agent');
 
   if (action === 'cancel') {
     await deleteTroubleshootSession(env.SESSION_KV, telegramUserId);