Add clear message when Generative Fill credits are exhausted

When Generative Fill runs out of monthly AI credits, Photoshop just shows the “Generating…” window and then closes without any explanation. It looks like the feature has failed or the app is broken. Please add a clear on-screen message (for example, “You’ve used all your generative credits — resets on [date]”) so users understand what’s happening instead of wasting time troubleshooting. This small UX improvement would save a lot of frustration.