Added a private extension method GetRequiredClaimOfSender to ClaimsPrincipal for retrieving the first available value from multiple claim types, throwing a detailed exception if none are found. Refactored GetId to use this method, improving code reuse and clarity when handling user claims.
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.
