feat: HR Portal - Complete Multi-Tenant System with Redis Session Storage

Major Features:
- ✅ Multi-tenant architecture (tenant isolation)
- ✅ Employee CRUD with lifecycle management (onboarding/offboarding)
- ✅ Department tree structure with email domain management
- ✅ Company info management (single-record editing)
- ✅ System functions CRUD (permission management)
- ✅ Email account management (multi-account per employee)
- ✅ Keycloak SSO integration (auth.lab.taipei)
- ✅ Redis session storage (10.1.0.254:6379)
  - Solves Cookie 4KB limitation
  - Cross-system session sharing
  - Sliding expiration (8 hours)
  - Automatic token refresh

Technical Stack:
Backend:
- FastAPI + SQLAlchemy
- PostgreSQL 16 (10.1.0.20:5433)
- Keycloak Admin API integration
- Docker Mailserver integration (SSH)
- Alembic migrations

Frontend:
- Next.js 14 (App Router)
- NextAuth 4 with Keycloak Provider
- Redis session storage (ioredis)
- Tailwind CSS

Infrastructure:
- Redis 7 (10.1.0.254:6379) - Session + Cache
- Keycloak 26.1.0 (auth.lab.taipei)
- Docker Mailserver (10.1.0.254)

Architecture Highlights:
- Session管理由 Keycloak + Redis 統一控制
- 支援多系統 (HR/WebMail/Calendar/Drive/Office) 共享 session
- Token 自動刷新,異質服務整合
- 未來可無縫遷移到雲端

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

backend/check_triggers.py

@@ -0,0 +1,46 @@
+"""
+檢查資料庫中的觸發器
+"""
+import psycopg2
+
+conn = psycopg2.connect(
+    host="10.1.0.20",
+    port=5433,
+    database="hr_portal",
+    user="admin",
+    password="DC1qaz2wsx"
+)
+cur = conn.cursor()
+
+# 查詢所有觸發器
+cur.execute("""
+    SELECT
+        trigger_name,
+        event_object_table,
+        action_statement
+    FROM information_schema.triggers
+    WHERE trigger_schema = 'public'
+    ORDER BY event_object_table, trigger_name;
+""")
+
+triggers = cur.fetchall()
+
+print("=== Database Triggers ===\n")
+
+if triggers:
+    current_table = None
+    for trig in triggers:
+        if trig[1] != current_table:
+            if current_table is not None:
+                print()
+            print(f"[{trig[1]}]")
+            current_table = trig[1]
+
+        print(f"  Trigger: {trig[0]}")
+        print(f"  Action: {trig[2][:80]}...")
+        print()
+else:
+    print("No triggers found")
+
+cur.close()
+conn.close()