Production deployment setup + feature complete

- Dockerfile + deploy.sh for Hetzner server
- Email verification via Better Auth + Resend
- Invite code flow (6-digit OTP, generate/join)
- Settlement share percent fix (payer vs debtor)
- OCR scanner fixes (date display, retry, viewfinder)
- app.json icon/splash/adaptive-icon configured
- iOS deployment target 15.5 (ML Kit requirement)
- DB migration 0014: household_invitations table

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/auth/package.json

@@ -14,8 +14,10 @@
     "@better-auth/expo": "catalog:",
     "@haushaltsApp/db": "workspace:*",
     "@haushaltsApp/env": "workspace:*",
+    "@types/nodemailer": "^7.0.11",
     "better-auth": "catalog:",
     "dotenv": "catalog:",
+    "nodemailer": "^8.0.2",
     "zod": "catalog:"
   },
   "devDependencies": {