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>

scripts/EXECUTE-FIX-POSTGRES.txt

@@ -0,0 +1,63 @@
+# ============================================
+# 修復 PostgreSQL 端口綁定
+# ============================================
+#
+# 複製以下命令到 Ubuntu Server 執行
+# SSH 登入: ssh ubuntu@10.1.0.254
+#
+# ============================================
+
+# 步驟 1: 檢查現有配置
+echo "Current PostgreSQL configuration:"
+docker ps | grep postgres
+docker port postgres
+
+# 步驟 2: 獲取 postgres 密碼 (如果不知道,設定一個新的)
+# 例如: POSTGRES_PASSWORD="yourpassword"
+POSTGRES_PASSWORD="DC1qaz2wsx"
+
+# 步驟 3: 檢查資料卷
+VOLUME_NAME=$(docker inspect postgres --format '{{range .Mounts}}{{if eq .Destination "/var/lib/postgresql/data"}}{{.Name}}{{end}}{{end}}' 2>/dev/null || echo "postgres-data")
+echo "Using volume: $VOLUME_NAME"
+
+# 步驟 4: 停止並移除舊容器 (資料不會遺失,在 volume 中)
+docker stop postgres
+docker rm postgres
+
+# 步驟 5: 重新啟動,綁定到所有網路介面 (0.0.0.0:5432)
+docker run -d \
+  --name postgres \
+  --restart unless-stopped \
+  -e POSTGRES_PASSWORD="$POSTGRES_PASSWORD" \
+  -e POSTGRES_INITDB_ARGS="--encoding=UTF-8 --locale=en_US.UTF-8" \
+  -e TZ=Asia/Taipei \
+  -p 0.0.0.0:5432:5432 \
+  -v ${VOLUME_NAME}:/var/lib/postgresql/data \
+  postgres:16
+
+# 步驟 6: 等待啟動
+echo "Waiting for PostgreSQL to start..."
+sleep 5
+
+# 步驟 7: 驗證
+echo ""
+echo "Verification:"
+docker ps | grep postgres
+docker port postgres
+docker exec postgres pg_isready -U postgres
+
+# 步驟 8: 檢查資料庫
+echo ""
+echo "Databases:"
+docker exec postgres psql -U postgres -lqt | cut -d \| -f 1 | grep -v "^$"
+
+echo ""
+echo "Testing hr_portal database:"
+docker exec postgres psql -U hr_user -d hr_portal -c "\dt"
+
+echo ""
+echo "=========================================="
+echo "  PostgreSQL is now accessible!"
+echo "=========================================="
+echo "Connection: postgresql://hr_user:DC1qaz2wsx@10.1.0.254:5432/hr_portal"
+echo ""