feat: add multi-environment support (development, staging, production)

- Replace dotenv with compile-time dart-define-from-file config per flavor
  - Add Android product flavors with applicationIdSuffix and per-flavor AndroidManifest
  - Add iOS build configurations, schemes, per-flavor plists and entitlements
  - Configure ProGuard rules for R8 compatibility with Entrust/Antelop SDK
  - Restructure assets into shared/ and per-flavor directories
  - Generate per-flavor launcher icons for Android and iOS
  - Refactor app initialization into initApp() with per-flavor entry points
  - Update asset paths across auth, home, profile, splash modules and sf_shared

modules/home/lib/src/features/goals/goals_screen.dart

@@ -134,7 +134,7 @@ class SavingsBlockState extends ConsumerState<SavingsBlock> {
         children: [
           Align(
             alignment: Alignment.topRight,
-            child: SvgPicture.asset("assets/images/ui/ahorros.svg"),
+            child: SvgPicture.asset("assets/shared/images/ahorros.svg"),
           ),
           Column(
             spacing: 24,
@@ -648,7 +648,7 @@ class TasksBlockState extends ConsumerState<TasksBlock> {
         children: [
           Align(
             alignment: Alignment.topRight,
-            child: SvgPicture.asset("assets/images/ui/tareas.svg"),
+            child: SvgPicture.asset("assets/shared/images/tareas.svg"),
           ),
           Column(
             spacing: 24,