Assignment/Object Creation fails for non-@ref/@ref:external properties when reusing a value object previously assigned to an @ref/@ref:external property.

## Summary
Assignment (and/or object creation) fails for properties without `@ref` / `@ref:external` metadata when the same value object instance was previously assigned to a different property that is decorated with `@ref` or `@ref:external`.

## Observed Behaviour
When a value object V is first assigned to a “tagged” property (e.g., propTagged annotated with `@ref` or `@ref:external`), subsequent attempts to assign that same object V to an “untagged” property (e.g., propPlain with no `@ref`/`@ref:external`) fail.

This can happen during:
- direct property assignment, and/or
- object construction / deserialization where the same value object is reused across properties.

## Expected Behavior
Reusing the same value object instance across different properties should not cause assignment/creation to fail solely due to metadata differences between the properties. If V is valid for propPlain by type/shape, it should assign successfully regardless of whether it was previously used with a `@ref` / `@ref:external` tagged property.

## Workaround
- Cloning/copying the value object before assigning to the untagged property.

Es sind keine Dateien, Tests oder Einstiegspunkte angegeben. Beginne damit, die Wiederverwendung eines Wertobjekts aus einer @ref- oder @ref:external-Eigenschaft an einer nicht getaggten Eigenschaft nachzustellen, und decke dabei sowohl die direkte Zuweisung als auch die Konstruktion oder Deserialisierung ab; abgeschlossen ist die Aufgabe, wenn eine gültige Wiederverwendung erfolgreich ist, ohne einen Clone zu erfordern.

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