Replaced nullable claim accessors with strict versions that throw exceptions if required claims are missing or invalid. Updated controller logic to use new methods and removed fallback/error handling for missing claims, ensuring stricter claim validation throughout the codebase.
Renamed the extension class for claims handling and added a private GetRequiredClaimOfSender method for ClaimsPrincipal. This method throws a detailed exception when a required claim is missing, improving error reporting and debugging.
