The Save to Collection button on the identification screen would remain
disabled after plant identification completed, requiring the user to tap
a prediction row before it would enable. This was caused by an @Observable
+ @State tracking issue where computed properties in SwiftUI view modifiers
don't always trigger re-renders when the underlying observable changes.
Replaced the empty .onChange workaround with a local @State property
(saveEnabled) that is explicitly updated when selectedPrediction or
saveState changes, ensuring the button state always reflects the current
ViewModel state.
Fixes#1
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
