feat: implement update functionality for receipt aliases and add corresponding tests

flutter/lib/features/import/presentation/receipt_import_tab.dart

@@ -498,6 +498,74 @@ class _ReceiptImportTabState extends ConsumerState<ReceiptImportTab> {
     setState(() {});
   }
 
+  Future<void> _editAliasForItem(int index) async {
+    final items = _items;
+    if (items == null || index < 0 || index >= items.length) return;
+
+    final item = items[index];
+    final edit = _edits[index];
+    final productId = edit?.productId;
+    final initialAlias = item.rawName.trim();
+
+    if (productId == null) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Välj produkt för raden innan du redigerar alias.')),
+      );
+      return;
+    }
+
+    final controller = TextEditingController(text: initialAlias);
+    final aliasName = await showDialog<String>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: const Text('Spara alias för raden'),
+        content: TextField(
+          controller: controller,
+          autofocus: true,
+          decoration: const InputDecoration(
+            labelText: 'Aliasnamn',
+            border: OutlineInputBorder(),
+          ),
+          onSubmitted: (value) => Navigator.pop(ctx, value.trim()),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx),
+            child: const Text('Avbryt'),
+          ),
+          FilledButton(
+            onPressed: () => Navigator.pop(ctx, controller.text.trim()),
+            child: const Text('Spara'),
+          ),
+        ],
+      ),
+    );
+    controller.dispose();
+
+    if (!mounted || aliasName == null) return;
+    if (aliasName.isEmpty) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Aliasnamn kan inte vara tomt.')),
+      );
+      return;
+    }
+
+    try {
+      await ref.read(adminRepositoryProvider).upsertReceiptAlias(
+            receiptName: aliasName,
+            productId: productId,
+            isGlobal: false,
+          );
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('Alias sparat.')),
+      );
+    } catch (e) {
+      if (!mounted) return;
+      showGlobalErrorDialog(context, 'Kunde inte uppdatera alias: $e');
+    }
+  }
+
   Future<void> _addSelected() async {
     final items = _items;
     if (items == null) return;
@@ -844,6 +912,7 @@ class _ReceiptImportTabState extends ConsumerState<ReceiptImportTab> {
                       i,
                       initialEntryMode: ImportProductEntryMode.create,
                     ),
+                    onAliasEditRequested: () => _editAliasForItem(i),
                     onDeleteRequested: () => _deleteItem(i),
                     matchedViaBadgeBuilder: _buildMatchedViaBadge,
                   );
@@ -877,6 +946,7 @@ class _ReceiptImportResultRow extends ConsumerWidget {
   final VoidCallback onEditRequested;
   final VoidCallback onSelectExistingRequested;
   final VoidCallback onCreateRequested;
+  final VoidCallback onAliasEditRequested;
   final VoidCallback onDeleteRequested;
   final Widget Function(ParsedReceiptItem item, ThemeData theme)
       matchedViaBadgeBuilder;
@@ -891,6 +961,7 @@ class _ReceiptImportResultRow extends ConsumerWidget {
     required this.onEditRequested,
     required this.onSelectExistingRequested,
     required this.onCreateRequested,
+    required this.onAliasEditRequested,
     required this.onDeleteRequested,
     required this.matchedViaBadgeBuilder,
   });
@@ -1088,7 +1159,7 @@ class _ReceiptImportResultRow extends ConsumerWidget {
           ],
         ),
         trailing: SizedBox(
-          width: 80,
+          width: 120,
           child: Row(
             mainAxisSize: MainAxisSize.min,
             children: [
@@ -1101,6 +1172,14 @@ class _ReceiptImportResultRow extends ConsumerWidget {
                     : (isSuggested ? Colors.orange : theme.colorScheme.tertiary),
                 size: 20,
               ),
+              if (hasProduct)
+                IconButton(
+                  icon: const Icon(Icons.drive_file_rename_outline, size: 18),
+                  onPressed: onAliasEditRequested,
+                  tooltip: 'Spara alias',
+                  constraints: const BoxConstraints(minWidth: 40, minHeight: 40),
+                  padding: const EdgeInsets.all(4),
+                ),
               IconButton(
                 icon: Icon(Icons.delete_outline, size: 18, color: theme.colorScheme.error),
                 onPressed: onDeleteRequested,