dead-man-switch-2.0/memory-bank/systemPatterns.md

# System Patterns - Dead Man Switch 2.0

## Mimari
```
┌─────────────────────────────────────────────────┐
│                   Next.js App                    │
├─────────────────┬───────────────────────────────┤
│    Frontend     │         API Routes            │
│  (React + RSC)  │    (Auth, CRUD, Cron)         │
└────────┬────────┴───────────────┬───────────────┘
         │                        │
         │ Web Crypto API         │ Prisma
         │ (encrypt/decrypt)      │
         │                        ▼
         │               ┌─────────────────┐
         │               │   PostgreSQL    │
         │               └─────────────────┘
         │                        │
         ▼                        ▼
┌─────────────────┐      ┌─────────────────┐
│  Cloudflare R2  │      │   Nodemailer    │
│  (encrypted     │      │   (SMTP)        │
│   files)        │      └─────────────────┘
└─────────────────┘
```

## Veritabanı Şeması (Draft)
- **User**: id, email, password, role, createdAt
- **Message**: id, userId, title, encryptedContent, isEncrypted, checkInInterval, lastCheckIn, nextDeadline, status
- **Recipient**: id, messageId, email, name
- **Attachment**: id, messageId, r2Key, encryptedName, size

## Güvenlik Patterns
- Şifreleme client-side (AES-256-GCM)
- Şifre hash'i sunucuya gönderilmez
- Derived key PBKDF2 ile üretilir
- Salt her mesaj için unique

## API Patterns
- REST endpoints under `/api/*`
- NextAuth session-based auth
- Zod validation