refactor: worker_id → user_id 전체 마이그레이션 (Phase 1-4)

sso_users.user_id를 단일 식별자로 통합. JWT에서 worker_id 제거,
department_id/is_production 추가. 백엔드 15개 모델, 11개 컨트롤러,
4개 서비스, 7개 라우트, 프론트엔드 32+ JS/11+ HTML 변환.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sso-auth-service/models/userModel.js

@@ -84,7 +84,10 @@ async function hashPassword(password) {
 async function findByUsername(username) {
   const db = getPool();
   const [rows] = await db.query(
-    'SELECT * FROM sso_users WHERE username = ? AND is_active = TRUE',
+    `SELECT s.*, d.department_id, d.department_name, d.is_production
+     FROM sso_users s
+     LEFT JOIN departments d ON s.department_id = d.department_id
+     WHERE s.username = ? AND s.is_active = TRUE`,
     [username]
   );
   return rows[0] || null;
@@ -93,7 +96,10 @@ async function findByUsername(username) {
 async function findById(userId) {
   const db = getPool();
   const [rows] = await db.query(
-    'SELECT * FROM sso_users WHERE user_id = ?',
+    `SELECT s.*, d.department_id, d.department_name, d.is_production
+     FROM sso_users s
+     LEFT JOIN departments d ON s.department_id = d.department_id
+     WHERE s.user_id = ?`,
     [userId]
   );
   return rows[0] || null;