Enable Better-Auth email verification with Resend

- Add emailVerification.sendVerificationEmail config to auth/src/auth.ts
  using Resend to send verification emails on sign-up
- Add resend npm package to auth/package.json
- Update auth/.env.example with RESEND_API_KEY and FROM_EMAIL
- Create VerifyEmail.tsx page with token verification flow,
  spinner UX, success/Error states, and resend option
- Update Register.tsx to redirect to /verify-email after signup
  instead of auto-navigating to dashboard
- Add /verify-email route to App.tsx
- Frontend shows 'check your email' step after registration

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/pages/VerifyEmail.tsx

@@ -110,4 +110,4 @@ export function VerifyEmail() {
       )}
     </div>
   );
-}
+}