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>

src/pages/Auth.tsx

@@ -1,5 +1,5 @@
 import { useState, useEffect } from 'react';
-import { useNavigate, Link } from 'react-router-dom';
+import { useNavigate, Link, useLocation } from 'react-router-dom';
 import { useAuth } from '@/hooks/useAuth';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
@@ -25,6 +25,7 @@ export default function Auth() {
   const [isResendOTP, setIsResendOTP] = useState(false); // Track if this is resend OTP for existing user
   const { signIn, signUp, user, sendAuthOTP, verifyAuthOTP, getUserByEmail } = useAuth();
   const navigate = useNavigate();
+  const location = useLocation();
 
   useEffect(() => {
     if (user) {
@@ -100,7 +101,9 @@ export default function Auth() {
         toast({ title: 'Error', description: error.message, variant: 'destructive' });
         setLoading(false);
       } else {
-        navigate('/dashboard');
+        // Get redirect from URL state or use default
+        const redirectTo = (location.state as any)?.redirectTo || '/dashboard';
+        navigate(redirectTo);
         setLoading(false);
       }
     } else {