second round of review

backend/validation.py

@@ -34,8 +34,8 @@ def validate_telegram(value: str | None) -> str | None:
     if not value.startswith("@"):
         return "Telegram handle must start with @"
     
-    handle = value[1:]  # Remove @
-    if len(handle) < 1:
+    handle = value[1:]
+    if not handle:
         return "Telegram handle must have at least one character after @"
     
     if len(handle) > 32: