[BUG] copying AAS recursively duplicates submodel references

[dbcvc]

To Reproduce

1. enable edit mode
2. create an AAS
3. create a submodel inside the AAS
4. go to Env "AdministrationShells"
5. click copy recursively
6. select the AAS created in step 2
7. the AAS now has two identical submodel references

Expected behavior
The copied AAS should be identical to the original one (only one submodel)

Desktop (please complete the following information):

• OS: Win 11
• Version v2025-10-21.alpha