Refactor payment service, fix DB session, and consolidate endpoints

- Fix critical NameError in database.py by restoring Session factory
- Refactor payment_service.py and crud.py to use shared constants.py and utils.py
- Deduplicate state mapping and input sanitization logic
- Move transaction amount calculation logic from CRUD to Router layer
- Enforce type safety in schemas using IntEnum for TransactionType/Status
- Move capture endpoint from transaction.py to payment.py (now /payments/capture)
- Update create_customer_profile signature for clarity

app/utils.py

@@ -0,0 +1,28 @@
+"""
+Utility functions shared across the EAMCO Authorize service.
+"""
+import re
+
+def sanitize_input(text, max_len, allow_spaces=False, is_zip=False):
+    """
+    Sanitize input string by removing invalid characters.
+    
+    Args:
+        text: Input text/number/value
+        max_len: Maximum length of the output string
+        allow_spaces: If True, allows spaces in the output
+        is_zip: If True, allows hyphens (for ZIP+4)
+        
+    Returns:
+        Sanitized string truncated to max_len
+    """
+    if not text:
+        return ""
+    
+    if is_zip:
+        pattern = r'[^a-zA-Z0-9-]'
+    else:
+        pattern = r'[^a-zA-Z0-9]' if not allow_spaces else r'[^a-zA-Z0-9\s]'
+        
+    sanitized = re.sub(pattern, '', str(text))
+    return sanitized.strip()[:max_len]