Fix email system and implement OTP confirmation flow

Email System Fixes:
- Fix email sending after payment: handle-order-paid now calls send-notification
  instead of send-email-v2 directly, properly processing template variables
- Fix order_created email timing: sent immediately after order creation,
  before payment QR code generation
- Update email templates to use short order ID (8 chars) instead of full UUID
- Add working "Akses Sekarang" buttons to payment_success and access_granted emails
- Add platform_url column to platform_settings for email links

OTP Verification Flow:
- Create dedicated /confirm-otp page for users who close registration modal
- Add link in checkout modal and email to dedicated OTP page
- Update OTP email template with better copywriting and dedicated page link
- Fix send-auth-otp to fetch platform settings for dynamic brand_name and platform_url
- Auto-login users after OTP verification in checkout flow

Admin Features:
- Add delete user functionality with cascade deletion of all related data
- Update IntegrasiTab to read/write email settings from platform_settings only
- Add test email template for email configuration testing

Cleanup:
- Remove obsolete send-consultation-reminder and send-test-email functions
- Update send-email-v2 to read email config from platform_settings
- Remove footer links (Ubah Preferensi/Unsubscribe) from email templates

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

supabase/shared/email-template-renderer.ts

@@ -218,11 +218,7 @@ export class EmailTemplateRenderer {
                                 <tr>
                                     <td align="left" style="font-size: 12px; line-height: 18px; font-family: monospace; color: #555;">
                                         <p style="margin: 0 0 10px 0; font-weight: bold;">{{brandName}}</p>
-                                        <p style="margin: 0 0 15px 0;">Email ini dikirim otomatis. Jangan membalas email ini.</p>
-                                        <p style="margin: 0;">
-                                            <a href="#" style="color: #000; text-decoration: underline;">Ubah Preferensi</a> &nbsp;|&nbsp;
-                                            <a href="#" style="color: #000; text-decoration: underline;">Unsubscribe</a>
-                                        </p>
+                                        <p style="margin: 0;">Email ini dikirim otomatis. Jangan membalas email ini.</p>
                                     </td>
                                 </tr>
                             </table>