Correction of flutter errors + Native iOS/Android

Senior Flutter + Native Developer iOS & Android Bug Fixes

Status
- App is live on both stores and stable.
- Codebase upgraded to Flutter 3.32.x with updated dependencies.
- Builds run, but previous developer failed to resolve remaining issues.

Issues to Fix

Core Functional Issues
1. iOS (Xcode 16, iOS SDK 17/18) — Selfie screen responsiveness: requires ~20 taps before reacting.

2–3. Method Channel / API Call Layer (related issues)
- Android (SDK 34) — Incorrect color payloads to server: stores black (= no color) instead of selected value.
- iOS Rendering — Green tint applied to faces (native layers OK; problem is in Flutter bridge).

4. iOS Slider Performance — Opacity slider stutters/lags; updates on every drag tick instead of on release (Android is smooth).

Simple UI Fixes
5. Navigation — Back arrow in selfie/analysis flow not working.
6. UI Cleanup — Remove line around button.
7. iOS Product Visualisation — Colours appear low/washed-out in product screens.
8. UI Scaling — Oversized buttons in some views.

Requirements (Must-Have)
- Senior Flutter engineer with strong Swift + Kotlin background.
- macOS with Xcode 16 + iOS SDK 17 device/simulator.
- Hands-on fixing: Flutter.h, modulemap, use_frameworks!, Bitcode off, xcframework conversions, plugin incompatibilities.
- Must produce signed release builds and upload to TestFlight v2.0.

Deliverables
- Fixed: selfie responsiveness, method channel issues (color persistence + green tint), slider smoothness, navigation, UI fixes.
- Release builds:
- iOS → uploaded to TestFlight v2.0
- Android → signed, ready for store
- Strictly bug fixes & compatibility. No new features.

Targets
- iOS: Xcode 16, iOS SDK 17/18, min iOS 13, Bitcode disabled, xcframework where required.
- Android: Target SDK 34, updated Gradle & Kotlin, proper signing for release.

Timeline
- Start: Immediately
- Delivery: 2–3 days maximum

Work Ethic & Professionalism
No juniors. No guesswork. No deflection.
I have 48 years in software, I expect precision and professionalism.
If you solve problems without excuses, apply.

Additional Requirement
- Push the app to both stores:
- TestFlight for iOS
- Google Play Test Track (APK) for Android