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/fix-postgres-remote.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+# Fix PostgreSQL port binding - Remote execution script
+
+POSTGRES_PASSWORD="DC1qaz2wsx"
+
+echo "=========================================="
+echo "  Reconfiguring PostgreSQL Container"
+echo "=========================================="
+echo ""
+
+echo "[1/4] Stopping old container..."
+docker stop postgres
+docker rm postgres
+
+echo ""
+echo "[2/4] Starting new container with external access..."
+docker run -d \
+  --name postgres \
+  --restart unless-stopped \
+  -e POSTGRES_PASSWORD="$POSTGRES_PASSWORD" \
+  -e POSTGRES_INITDB_ARGS="--encoding=UTF-8 --locale=en_US.UTF-8" \
+  -e TZ=Asia/Taipei \
+  -p 0.0.0.0:5432:5432 \
+  -v postgres-data:/var/lib/postgresql/data \
+  postgres:16
+
+echo ""
+echo "[3/4] Waiting for PostgreSQL to be ready..."
+sleep 5
+
+for i in {1..20}; do
+    if docker exec postgres pg_isready -U postgres >/dev/null 2>&1; then
+        echo "  PostgreSQL is ready!"
+        break
+    fi
+    echo "  Waiting... ($i/20)"
+    sleep 1
+done
+
+echo ""
+echo "[4/4] Verifying configuration..."
+echo ""
+echo "Container status:"
+docker ps | grep postgres
+
+echo ""
+echo "Port binding:"
+docker port postgres
+
+echo ""
+echo "Database check:"
+docker exec postgres psql -U hr_user -d hr_portal -c "SELECT COUNT(*) as table_count FROM information_schema.tables WHERE table_schema='public' AND table_type='BASE TABLE';"
+
+echo ""
+echo "=========================================="
+echo "  Configuration Complete!"
+echo "=========================================="
+echo ""
+echo "PostgreSQL is now accessible from 10.1.0.254:5432"
+echo ""