fix(dashboard): workers 없는 사용자 부서 권한 조회 수정

getUserInfo에서 workers.department_id만 사용하여
workers 레코드가 없는 사용자(생산지원팀 등)의 department_id가
NULL이 되어 메뉴가 안 보이던 문제.
COALESCE(w.department_id, u.department_id) fallback 추가.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

system1-factory/api/models/dashboardModel.js

@@ -14,11 +14,13 @@ const DashboardModel = {
     const db = await getDb();
     const [rows] = await db.execute(`
       SELECT u.user_id, u.name, u.role,
-             w.worker_id, w.worker_name, w.job_type, w.department_id,
-             COALESCE(d.department_name, '미배정') AS department_name
+             w.worker_id, w.worker_name, w.job_type,
+             COALESCE(w.department_id, u.department_id) AS department_id,
+             COALESCE(d.department_name, d2.department_name, '미배정') AS department_name
       FROM sso_users u
       LEFT JOIN workers w ON u.user_id = w.user_id
       LEFT JOIN departments d ON w.department_id = d.department_id
+      LEFT JOIN departments d2 ON u.department_id = d2.department_id
       WHERE u.user_id = ?
     `, [userId]);
     return rows[0] || null;