Upgrade dependencies, fix Android/iOS build + UI deprecations (Flutter dev env)

[chaturadilan]

Summary

Sets up the Cursor Cloud dev environment for this Flutter package and upgrades its outdated dependencies so it actually compiles into an app again, fixing all resulting code/UI breakages.

Why

The repo's pinned deps (network_to_file_image 3.1.0, firebase_* 3.x) predate Dart 2.15+ interface changes and could not be compiled into an app on any Dart version satisfying the rest of the lockfile (flutter >= 2.10). develop is identical to main and release/v4.3.0 keeps the same pins, so the fix required upgrading dependencies directly.

Changes

• Dependency upgrades (pubspec.yaml): network_to_file_image 4.x, firebase_auth 4.x, cloud_firestore 4.x, firebase_storage 11.x, firebase_analytics 10.x, image_cropper 4.x, image_picker 1.x, flutter_facebook_auth 5.x, sign_in_with_apple 5.x, google_sign_in 6.x, flutter_form_builder/form_builder_validators 8.x, carousel_slider 5.x, google_fonts 4.x, font_awesome_flutter 10.x, package_info_plus 4.x, loading_overlay 0.5.x, logger 2.x. Added crypto/path as direct deps. Kept sizer at 2.0.15 (3.x drops DeviceType.mobile/tablet and clashes with get on ScreenType).
• Code migrations: FormBuilderValidators without context; ImageCropper().cropImage(... uiSettings: [...]) returning CroppedFile; CarouselSliderController; LoadingOverlay without opacity; FormBuilderDropdown hint via decoration.hintText.
• UI deprecation fixes: ElevatedButton.styleFrom primary/onPrimary → backgroundColor/foregroundColor; textTheme.headline6 → titleLarge; logger printTime → dateTimeFormat; removed a duplicate import; sorted child last.
• Environment: Flutter 3.7.12/Dart 2.19.6, Android SDK (android-33), JDK 17. Update script: flutter pub get. AGENTS.md documents the toolchain + build caveats (host app needs minSdkVersion 21; flutter clean before web after the package_info_plus major bump).

Verification

• flutter analyze → No issues found!
• Android flutter build apk --debug (example app consuming the package) → builds an 85 MB APK.
• flutter build web → builds successfully.
• Ran the example in Chrome and confirmed the package's real LoginButton widget renders and is interactive (counter increments on click).
• iOS: not buildable on Linux (flutter build ios unavailable; requires macOS + Xcode).

Walkthrough

flexus_upgraded_web_demo.mp4
Upgraded framework's LoginButton rendering and incrementing the counter on click.

App loaded, Clicked: 0
Counter at 3 after clicks

flexus_build_success.log

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