feat: Implement major features and fix theming bug

This commit introduces several new features and a critical bug fix.

- Implemented a full "Quick Pay" flow for both within and outside the bank, including IFSC validation, beneficiary verification, and a TPIN-based payment process.
- Added a date range filter to the Account Statement screen and streamlined the UI by removing the amount filters.
- Fixed a major bug that prevented dynamic theme changes from being applied. The app now correctly switches between color themes.
- Refactored and improved beneficiary management, transaction models, and the fund transfer flow to support NEFT/RTGS.

lib/features/dashboard/widgets/account_card.dart

@@ -13,14 +13,15 @@ class AccountCard extends StatelessWidget {
       width: 300,
       padding: const EdgeInsets.all(20),
       decoration: BoxDecoration(
-        gradient: LinearGradient(
-          begin: Alignment.topLeft,
-          end: Alignment.bottomRight,
-          colors: [
-            Theme.of(context).primaryColor,
-            Theme.of(context).primaryColor.withBlue(200),
-          ],
-        ),
+        // gradient: LinearGradient(
+        //   begin: Alignment.topLeft,
+        //   end: Alignment.bottomRight,
+        //   colors: [
+        //     Theme.of(context).primaryColor,
+        //     Theme.of(context).primaryColor.withBlue(200),
+        //   ],
+        // ),
+        color: Theme.of(context).primaryColor,
         borderRadius: BorderRadius.circular(12),
         boxShadow: [
           BoxShadow(
@@ -56,12 +57,13 @@ class AccountCard extends StatelessWidget {
           const SizedBox(height: 20),
           Text(
             account.accountNumber,
-            style: TextStyle(color: Theme.of(context).dialogBackgroundColor, fontSize: 16),
+            style: TextStyle(
+                color: Theme.of(context).dialogBackgroundColor, fontSize: 16),
           ),
           const SizedBox(height: 30),
           Text(
             '${account.currency} ${account.balance.toStringAsFixed(2)}',
-            style:  TextStyle(
+            style: TextStyle(
               color: Theme.of(context).scaffoldBackgroundColor,
               fontSize: 22,
               fontWeight: FontWeight.bold,
@@ -70,7 +72,8 @@ class AccountCard extends StatelessWidget {
           const SizedBox(height: 5),
           Text(
             AppLocalizations.of(context).availableBalance,
-            style: TextStyle(color: Theme.of(context).dialogBackgroundColor, fontSize: 12),
+            style: TextStyle(
+                color: Theme.of(context).dialogBackgroundColor, fontSize: 12),
           ),
         ],
       ),