Refactor screens to MVC architecture with modular widgets

- Extract business logic from screens into dedicated controllers
- Split large screen files into smaller, reusable widget components
- Add controllers for AddSubscriptionScreen and DetailScreen
- Create modular widgets for subscription and detail features
- Improve code organization and maintainability
- Remove duplicated code and improve reusability

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

lib/theme/adaptive_theme.dart

@@ -13,7 +13,7 @@ class AdaptiveTheme {
     return ThemeData(
       useMaterial3: true,
       brightness: Brightness.dark,
-      colorScheme: ColorScheme.dark(
+      colorScheme: const ColorScheme.dark(
         primary: AppColors.primaryColor,
         onPrimary: Colors.white,
         secondary: AppColors.secondaryColor,
@@ -134,11 +134,11 @@ class AdaptiveTheme {
         ),
         focusedBorder: OutlineInputBorder(
           borderRadius: BorderRadius.circular(12),
-          borderSide: BorderSide(color: AppColors.primaryColor, width: 1.5),
+          borderSide: const BorderSide(color: AppColors.primaryColor, width: 1.5),
         ),
         errorBorder: OutlineInputBorder(
           borderRadius: BorderRadius.circular(12),
-          borderSide: BorderSide(color: AppColors.dangerColor, width: 1),
+          borderSide: const BorderSide(color: AppColors.dangerColor, width: 1),
         ),
         labelStyle: TextStyle(
           color: Colors.white.withValues(alpha: 0.7),

lib/theme/app_theme.dart

@@ -4,7 +4,7 @@ import 'app_colors.dart';
 class AppTheme {
   static ThemeData lightTheme = ThemeData(
     useMaterial3: true,
-    colorScheme: ColorScheme.light(
+    colorScheme: const ColorScheme.light(
       primary: AppColors.primaryColor,
       onPrimary: Colors.white,
       secondary: AppColors.secondaryColor,
@@ -24,48 +24,48 @@ class AppTheme {
       shadowColor: Colors.black.withValues(alpha: 0.04),
       shape: RoundedRectangleBorder(
         borderRadius: BorderRadius.circular(16),
-        side: BorderSide(color: AppColors.borderColor, width: 0.5),
+        side: const BorderSide(color: AppColors.borderColor, width: 0.5),
       ),
       clipBehavior: Clip.antiAlias,
       margin: const EdgeInsets.symmetric(vertical: 8, horizontal: 16),
     ),
 
     // 앱바 스타일 - 깔끔하고 투명한 디자인
-    appBarTheme: AppBarTheme(
+    appBarTheme: const AppBarTheme(
       backgroundColor: AppColors.surfaceColor,
       foregroundColor: AppColors.textPrimary,
       elevation: 0,
       centerTitle: false,
-      titleTextStyle: TextStyle(
+      titleTextStyle: const TextStyle(
         color: AppColors.textPrimary,
         fontSize: 22,
         fontWeight: FontWeight.w600,
         letterSpacing: -0.2,
       ),
-      iconTheme: IconThemeData(
+      iconTheme: const IconThemeData(
         color: AppColors.secondaryColor,
         size: 24,
       ),
     ),
 
     // 타이포그래피 - Metronic Tailwind 스타일
-    textTheme: TextTheme(
+    textTheme: const TextTheme(
       // 헤드라인 - 페이지 제목
-      headlineLarge: TextStyle(
+      headlineLarge: const TextStyle(
         color: AppColors.textPrimary,
         fontSize: 32,
         fontWeight: FontWeight.w700,
         letterSpacing: -0.5,
         height: 1.2,
       ),
-      headlineMedium: TextStyle(
+      headlineMedium: const TextStyle(
         color: AppColors.textPrimary,
         fontSize: 28,
         fontWeight: FontWeight.w700,
         letterSpacing: -0.5,
         height: 1.2,
       ),
-      headlineSmall: TextStyle(
+      headlineSmall: const TextStyle(
         color: AppColors.textPrimary,
         fontSize: 24,
         fontWeight: FontWeight.w600,
@@ -74,7 +74,7 @@ class AppTheme {
       ),
 
       // 타이틀 - 카드, 섹션 제목
-      titleLarge: TextStyle(
+      titleLarge: const TextStyle(
         color: AppColors.textPrimary,
         fontSize: 20,
         fontWeight: FontWeight.w600,
@@ -154,31 +154,31 @@ class AppTheme {
       ),
       enabledBorder: OutlineInputBorder(
         borderRadius: BorderRadius.circular(12),
-        borderSide: BorderSide(color: AppColors.borderColor, width: 1),
+        borderSide: const BorderSide(color: AppColors.borderColor, width: 1),
       ),
       focusedBorder: OutlineInputBorder(
         borderRadius: BorderRadius.circular(12),
-        borderSide: BorderSide(color: AppColors.primaryColor, width: 1.5),
+        borderSide: const BorderSide(color: AppColors.primaryColor, width: 1.5),
       ),
       errorBorder: OutlineInputBorder(
         borderRadius: BorderRadius.circular(12),
-        borderSide: BorderSide(color: AppColors.dangerColor, width: 1),
+        borderSide: const BorderSide(color: AppColors.dangerColor, width: 1),
       ),
       focusedErrorBorder: OutlineInputBorder(
         borderRadius: BorderRadius.circular(12),
-        borderSide: BorderSide(color: AppColors.dangerColor, width: 1.5),
+        borderSide: const BorderSide(color: AppColors.dangerColor, width: 1.5),
       ),
-      labelStyle: TextStyle(
+      labelStyle: const TextStyle(
         color: AppColors.textSecondary,
         fontSize: 14,
         fontWeight: FontWeight.w500,
       ),
-      hintStyle: TextStyle(
+      hintStyle: const TextStyle(
         color: AppColors.textMuted,
         fontSize: 14,
         fontWeight: FontWeight.w400,
       ),
-      errorStyle: TextStyle(
+      errorStyle: const TextStyle(
         color: AppColors.dangerColor,
         fontSize: 12,
         fontWeight: FontWeight.w400,
@@ -230,7 +230,7 @@ class AppTheme {
         shape: RoundedRectangleBorder(
           borderRadius: BorderRadius.circular(12),
         ),
-        side: BorderSide(color: AppColors.borderColor, width: 1),
+        side: const BorderSide(color: AppColors.borderColor, width: 1),
         textStyle: const TextStyle(
           fontSize: 15,
           fontWeight: FontWeight.w600,
@@ -282,7 +282,7 @@ class AppTheme {
       shape: RoundedRectangleBorder(
         borderRadius: BorderRadius.circular(4),
       ),
-      side: BorderSide(color: AppColors.borderColor, width: 1.5),
+      side: const BorderSide(color: AppColors.borderColor, width: 1.5),
     ),
 
     // 라디오 버튼 스타일
@@ -307,16 +307,16 @@ class AppTheme {
     ),
 
     // 탭바 스타일
-    tabBarTheme: TabBarTheme(
+    tabBarTheme: const TabBarTheme(
       labelColor: AppColors.primaryColor,
       unselectedLabelColor: AppColors.textSecondary,
       indicatorColor: AppColors.primaryColor,
-      labelStyle: TextStyle(
+      labelStyle: const TextStyle(
         fontSize: 14,
         fontWeight: FontWeight.w600,
         letterSpacing: 0.1,
       ),
-      unselectedLabelStyle: TextStyle(
+      unselectedLabelStyle: const TextStyle(
         fontSize: 14,
         fontWeight: FontWeight.w500,
         letterSpacing: 0.1,
@@ -324,7 +324,7 @@ class AppTheme {
     ),
 
     // 디바이더 스타일
-    dividerTheme: DividerThemeData(
+    dividerTheme: const DividerThemeData(
       color: AppColors.dividerColor,
       thickness: 1,
       space: 16,
@@ -342,7 +342,7 @@ class AppTheme {
     // 스낵바 스타일
     snackBarTheme: SnackBarThemeData(
       backgroundColor: AppColors.textPrimary,
-      contentTextStyle: TextStyle(
+      contentTextStyle: const TextStyle(
         color: Colors.white,
         fontSize: 14,
         fontWeight: FontWeight.w500,