chore: upgrade melos to 7.5.1 with pub workspaces and dep catalog

- Upgrade Melos to 7.5.1 using Dart pub workspaces (Melos 7 paradigm).
- Replace per-package pubspec_overrides.yaml with workspace-native resolution. Add dependencies.yaml as a centralized catalog for all external deps with sync_deps.dart tool to propagate and validate versions across the monorepo.

apps/mobile_app/pubspec.yaml

@@ -3,6 +3,7 @@ description: "A new Flutter project."
 # The following line prevents the package from being accidentally published to
 # pub.dev using `flutter pub publish`. This is preferred for private packages.
 publish_to: 'none' # Remove this line if you wish to publish to pub.dev
+resolution: workspace
 
 # The following defines the version and build number for your application.
 # A version number is three numbers separated by dots, like 1.2.43
@@ -90,7 +91,7 @@ dependencies:
     path: ../../packages/payments
   #dependencies go here
   cupertino_icons: ^1.0.8
-  flutter_svg: ^2.2.1
+  flutter_svg: ^2.2.2
   go_router_builder: ^4.1.1
   build_runner: ^2.7.1