[App] Model Swap Update

Model Swap Improvements

• Model Swap now delivers hyper-realistic results with stronger prompt adherence and seamless blending between the new identity and original clothing.

• Background changes are handled directly in the prompt. If you request a new background, it will be applied; if not, the background remains unchanged.

Backward Compatibility Note

• This upgrade is not yet fully compatible with Consistent Models. If you select a consistent model, the system will fall back to the previous technique so your trained models remain usable.

• Backgrounds will not change by default in this mode. For background edits, we recommend using the Edit tool instead of the old background toggle.

Check it out now: https://app.fashn.ai/models/change-appearance