Fix of an error when booking

Website/main.py

@@ -414,9 +414,11 @@ def _select_booking_admin() -> dict | None:
     return None
 
 
-def _sanitize_text(text: str, max_length: int = 255) -> str:
+def _sanitize_text(text: object, max_length: int = 255) -> str:
     """Sanitize user text input: strip, limit length, and escape HTML."""
-    text = (text or "").strip()
+    if not isinstance(text, str):
+        return ""
+    text = text.strip()
     if len(text) > max_length:
         text = text[:max_length]
     return text