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>

apps/native/.env.example

@@ -0,0 +1,2 @@
+EXPO_PUBLIC_SERVER_URL=http://localhost:3000
+EXPO_PUBLIC_WS_URL=ws://localhost:3000