NFC payment: New animation and polish motion (reduced-motion + faster timings)

[swedishfrenchpress]

Summary

This PR ports the WebView-based NFC payment animation from erik_nfc_animation_v4 to the current branch and applies motion design best practices based on Emil Kowalski, Jakub Krehel, and accessibility guidelines.

Changes

NFC Animation Migration

• Replaced native NfcPaymentAnimationView with WebView-based animation (nfc_animation.html)
• Added organic blob morphing effect during payment processing
• Added "Done" close button that appears after successful payment
• Implemented fullscreen mode during animation with proper system bar handling
• Added 10-second safety timeout for NFC payments

Motion Design Improvements

• Accessibility: Added prefers-reduced-motion media query support (critical for users with vestibular disorders)
• Speed: Reduced total animation time from ~2+ seconds to ~500ms for production use
• Natural motion: Changed all scale(0) animations to scale(0.9) for gentler, more natural movement
• Polish: Added blur effect to result text ("materializing" enter animation)
• Professional feel: Replaced bouncy easing curves with smooth deceleration
• Simplified morphing: Reduced blob animation from aggressive 4-step to subtle 2-step breathing

Timing Changes

Animation	Before	After
Phase duration	600ms	250ms
Min animation time	1200ms	400ms
Check circle transition	500ms	350ms
Fade in/out	300ms	200ms

New Files

• app/src/main/assets/nfc_animation.html - WebView animation
• app/src/main/res/anim/fade_in.xml - Activity fade transition
• app/src/main/res/anim/fade_out.xml - Activity fade transition
• app/src/main/res/drawable/bg_button_black_pill.xml - Close button background
• app/src/main/res/drawable-night/bg_button_black_pill.xml - Dark mode variant

Modified Files

• PaymentRequestActivity.kt - WebView setup, animation callbacks, fullscreen handling
• activity_payment_request.xml - Replaced custom view with WebView container
• strings.xml - Added close button text

[a1denvalu3]

@swedishfrenchpress It looks like NfcPaymentAnimationView.kt is not used anywhere in the codebase.

[swedishfrenchpress]

It looks like NfcPaymentAnimationView.kt is not used anywhere in the codebase.

good catch. i verified this with my AI and just pushed a commit.

[swedishfrenchpress]

update on latest changes:

Payment Animation Changes (Native Migration)

What changed

• Replaced the NFC payment animation WebView path with a native Android view:
  • NfcPaymentAnimationView in PaymentRequestActivity.
• Unified success in PaymentRequestActivity to the native green full-screen result UI.
• Added success actions on the overlay:
  • View Details
  • Done
• Updated failure overlay actions to:
  • Try again
  • Close
• Stopped routing overlay-close on failure to the old failure screen.
• Modernized PaymentFailureActivity to the red visual style so old white failure design is retired app-wide.
• Reduced duplication by centralizing resume/details intent creation in:
  • PaymentIntentFactory

Why native is better than the old WebView here

• Removes WebView load/bridge timing from this payment animation path.
• Reduces risk of delayed animation start and state-sync issues.
• Uses direct native rendering/animation for more reliable transitions on POS devices.

Notes

• Payment protocol logic was not changed (Cashu/NFC/Lightning flow behavior preserved).
• Known existing build blocker remains unrelated to these UI changes:
  • Cashu SDK class version mismatch (65.0 vs 61.0) during full assembleDebug.

[swedishfrenchpress]

@a1denvalu3 i think this is ready to do. i haven't pushed any changes. it's been to challenging to get the nfc processing screen to animate. i think for launch we can live with this.