What are Mule 4 error handling namespaces?

Mule 4 errors follow a NAMESPACE:ERROR_IDENTIFIER pattern. Key namespaces: HTTP: Connector errors — HTTP:CONNECTIVITY, HTTP:NOT_FOUND, HTTP:UNAUTHORIZED, HTTP:TIMEOUT, HTTP:BAD_REQUEST, HTTP:METHOD_NOT_ALLOWED. MULE: Core runtime errors — MULE:EXPRESSION (DataWeave evaluation failure), MULE:ROUTING, MULE:SERVER_SECURITY, MULE:CONNECTIVITY, MULE:RETRY_EXHAUSTED. EXPRESSION: DataWeave/MEL expression errors. ANY: Wildcard — catches all error types. Error types have a hierarchy — parent types can catch child errors. Example: HTTP:CLIENT_SECURITY_ERROR is a child of HTTP. On Error handlers match errors using type attribute — specify comma-separated types for multiple: type="HTTP:UNAUTHORIZED, HTTP:FORBIDDEN". Custom errors can be raised using the Raise Error component: <raise-error type="ORDER:INSUFFICIENT_STOCK" description="Stock unavailable"/>.