Unqualified shared property assignment in shared method fails at runtime

Unqualified access to a shared property from a shared method on the same class can fail when the shared method assigns the property. The property exists, but the runtime reports Undefined variable 'SharedInstance' instead of treating the bare name as the class shared property.

Expected behaviour: inside a shared method, a same-class shared property such as SharedInstance should resolve like Initialisation.SharedInstance for both reads and writes.