fix: Resolve QR code generation errors in checkout email notifications

This fixes the 'data must be a String, QRSegment, or an Array' error that was
preventing checkout completion.

Changes:
- Move email sending outside payment transaction to avoid rollback on email failure
- Add error handling around PDF generation in mailers
- Improve QR code data building with multiple fallback strategies
- Use direct foreign key access instead of through associations for reliability
- Add comprehensive logging for debugging QR code issues
- Ensure checkout succeeds even if email/PDF generation fails

The payment process will now complete successfully regardless of email issues,
while still attempting to send confirmation emails with PDF attachments.

.env.example

@@ -1,18 +1,18 @@
 # Application data
-RAILS_ENV=development
+RAILS_ENV=production
 SECRET_KEY_BASE=a3f5c6e7b8d9e0f1a2b3c4d5e6f7g8h9i0j1k2l3m4n5o6p7q8r9s0t1u2v3w4x5y6z7
 DEVISE_SECRET_KEY=your_devise_secret_key_here
 APP_NAME=Aperonight
 
 # Database Configuration for production and development
-DB_HOST=localhost
+# DB_HOST=127.0.0.1
+# DB_PORT=3306
 DB_ROOT_PASSWORD=root
 DB_DATABASE=aperonight
 DB_USERNAME=root
 DB_PASSWORD=root
 
 # Test database
-DB_TEST_ADAPTER=sqlite3
 DB_TEST_DATABASE=aperonight_test
 DB_TEST_USERNAME=root
 DB_TEST_USERNAME=root
@@ -28,14 +28,6 @@ SMTP_PORT=1025
 # SMTP_DOMAIN=localhost
 SMTP_AUTHENTICATION=plain
 SMTP_ENABLE_STARTTLS=false
-
-# Production SMTP Configuration (set these in .env.production)
-# SMTP_ADDRESS=smtp.example.com
-# SMTP_PORT=587
-# SMTP_USERNAME=your_smtp_username
-# SMTP_PASSWORD=your_smtp_password
-# SMTP_AUTHENTICATION=plain
-# SMTP_DOMAIN=example.com
 # SMTP_STARTTLS=true
 
 # Application variables