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/setup-ssh-key.ps1

@@ -0,0 +1,119 @@
+# Setup SSH Key-based Authentication
+# This script configures passwordless SSH login to Ubuntu Server
+
+$ErrorActionPreference = "Stop"
+
+Write-Host "========================================" -ForegroundColor Cyan
+Write-Host "  SSH Key Setup for Ubuntu Server" -ForegroundColor Cyan
+Write-Host "========================================" -ForegroundColor Cyan
+Write-Host ""
+
+$SSH_DIR = "$env:USERPROFILE\.ssh"
+$SSH_KEY = "$SSH_DIR\id_rsa"
+$SSH_PUB = "$SSH_KEY.pub"
+$REMOTE_HOST = "ubuntu@10.1.0.254"
+
+# Step 1: Check if SSH directory exists
+Write-Host "[1/4] Checking SSH directory..." -ForegroundColor Yellow
+
+if (-not (Test-Path $SSH_DIR)) {
+    Write-Host "  Creating .ssh directory..." -ForegroundColor Gray
+    New-Item -ItemType Directory -Path $SSH_DIR -Force | Out-Null
+    Write-Host "  [OK] Directory created" -ForegroundColor Green
+} else {
+    Write-Host "  [OK] Directory exists" -ForegroundColor Green
+}
+
+Write-Host ""
+
+# Step 2: Generate SSH key if not exists
+Write-Host "[2/4] Checking for SSH key..." -ForegroundColor Yellow
+
+if (Test-Path $SSH_PUB) {
+    Write-Host "  [OK] SSH key already exists" -ForegroundColor Green
+    Write-Host "  Key location: $SSH_KEY" -ForegroundColor Gray
+    Write-Host ""
+    Write-Host "  Public key content:" -ForegroundColor Gray
+    Get-Content $SSH_PUB | Write-Host -ForegroundColor White
+} else {
+    Write-Host "  Generating new SSH key pair..." -ForegroundColor Gray
+    Write-Host "  (Press Enter when prompted for passphrase to skip)" -ForegroundColor Yellow
+
+    ssh-keygen -t rsa -b 4096 -f $SSH_KEY -C "windows-to-ubuntu"
+
+    if ($LASTEXITCODE -eq 0) {
+        Write-Host "  [OK] SSH key generated successfully" -ForegroundColor Green
+    } else {
+        Write-Host "  [FAIL] Failed to generate SSH key" -ForegroundColor Red
+        exit 1
+    }
+}
+
+Write-Host ""
+
+# Step 3: Copy public key to remote server
+Write-Host "[3/4] Copying public key to Ubuntu Server..." -ForegroundColor Yellow
+Write-Host "  You will need to enter the Ubuntu password ONE TIME" -ForegroundColor Yellow
+Write-Host ""
+
+try {
+    # Read public key content
+    $pubKeyContent = Get-Content $SSH_PUB -Raw
+
+    # Create command to add key to authorized_keys
+    $remoteCommand = @"
+mkdir -p ~/.ssh && \
+chmod 700 ~/.ssh && \
+echo '$pubKeyContent' >> ~/.ssh/authorized_keys && \
+chmod 600 ~/.ssh/authorized_keys && \
+echo 'SSH key added successfully'
+"@
+
+    # Execute remote command
+    Write-Host "  Connecting to $REMOTE_HOST..." -ForegroundColor Gray
+    ssh $REMOTE_HOST $remoteCommand
+
+    if ($LASTEXITCODE -eq 0) {
+        Write-Host "  [OK] Public key copied successfully" -ForegroundColor Green
+    } else {
+        Write-Host "  [FAIL] Failed to copy public key" -ForegroundColor Red
+        exit 1
+    }
+} catch {
+    Write-Host "  [ERROR] $($_.Exception.Message)" -ForegroundColor Red
+    exit 1
+}
+
+Write-Host ""
+
+# Step 4: Test passwordless login
+Write-Host "[4/4] Testing passwordless SSH login..." -ForegroundColor Yellow
+
+try {
+    $testResult = ssh -o BatchMode=yes -o ConnectTimeout=5 $REMOTE_HOST "echo 'Success'"
+
+    if ($LASTEXITCODE -eq 0 -and $testResult -eq "Success") {
+        Write-Host "  [OK] Passwordless login works!" -ForegroundColor Green
+    } else {
+        Write-Host "  [FAIL] Passwordless login test failed" -ForegroundColor Red
+        Write-Host "  You may need to restart SSH service on Ubuntu Server" -ForegroundColor Yellow
+        Write-Host "  Command: sudo systemctl restart ssh" -ForegroundColor Gray
+        exit 1
+    }
+} catch {
+    Write-Host "  [ERROR] Test failed: $($_.Exception.Message)" -ForegroundColor Red
+    exit 1
+}
+
+Write-Host ""
+Write-Host "========================================" -ForegroundColor Cyan
+Write-Host "  Setup Completed!" -ForegroundColor Cyan
+Write-Host "========================================" -ForegroundColor Cyan
+Write-Host ""
+Write-Host "You can now run commands without password:" -ForegroundColor Green
+Write-Host "  ssh $REMOTE_HOST 'docker ps'" -ForegroundColor White
+Write-Host "  ssh $REMOTE_HOST 'docker exec postgres psql -U postgres -l'" -ForegroundColor White
+Write-Host ""
+Write-Host "Next step:" -ForegroundColor Yellow
+Write-Host "  Run check-postgres.ps1 to verify PostgreSQL connection" -ForegroundColor White
+Write-Host ""