Variable-driven variant switch instance drops overrides

Summary

When a nested instance has its variant property bound to a variable, changing the variable's value (via mode switch) correctly switches the variant but resets instance swap overrides to their defaults.

Steps to reproduce

1. Create a component set Button with:
   • Variant property: State (enabled, disabled)
   • Exposed instance swap property: Icon (default: any icon)
   • Add a text varinat
2. Create a variable collection with two modes (e.g. "rest" and "disabled")
3. Add a string variable button/state with values: rest → "enabled", disabled → "disabled"
4. Create a second component Wrapper and place a Button instance inside it
5. Inside Wrapper, override the Button's Icon to a different icon, and update the text string
6. Inside Wrapper, bind the Button's State variant to the button/state variable
7. Place an instance of Wrapper on the canvas
8. Switch modes on the Wrapper instance

Expected

Button switches State. Icon/Text override persists.

Actual

Button switches State. Icon override resets to the component default.

Notes

• Manual variant switching on the same nested instance preserves the override
• Variable-driven switching on a top-level instance (not nested) preserves the override
• Only the combination of variable-driven + nested instance loses overrides