feat: Refactor routing and navigation structure with StatefulShellRoute

- Introduced a new function `_shellBranchIndexForPath` to determine the index of the shell branch based on the path.
- Replaced `ShellRoute` with `StatefulShellRoute.indexedStack` for better state management during navigation.
- Updated `AppShell` to handle navigation path changes and integrate with the new routing structure.
- Organized routes into `StatefulShellBranch` for better modularity and clarity.
- Enhanced admin panel functionality with improved alias management and UI updates.
- Added new methods in `ReceiptImportSessionNotifier` for managing selected items and edits more efficiently.
- Improved UI components in receipt import and admin panels for better performance and user experience.
- Added PageStorageKeys to various ListViews to maintain scroll positions across navigation.
- Documented performance goals and profiling strategies in a new PERFORMANCE.md file.

flutter/lib/features/admin/presentation/admin_users_panel.dart

@@ -328,10 +328,8 @@ class _AdminUsersPanelState extends ConsumerState<AdminUsersPanel> {
     }
 
     final list = ListView.builder(
-      shrinkWrap: widget.embedded,
-      physics: widget.embedded
-          ? const NeverScrollableScrollPhysics()
-          : null,
+      shrinkWrap: false,
+      physics: null,
       padding: widget.embedded
           ? EdgeInsets.zero
           : const EdgeInsets.fromLTRB(16, 8, 16, 80),
@@ -376,7 +374,7 @@ class _AdminUsersPanelState extends ConsumerState<AdminUsersPanel> {
           label: Text(context.l10n.adminNewUser),
         ),
         const SizedBox(height: 16),
-        list,
+        Expanded(child: list),
       ],
     );
   }