feat: implement alias strategy for receipt import with user-scoped and global fallback, enhance validation and normalization, and update UI components

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

@@ -19,6 +19,7 @@ class EditDialog extends StatefulWidget {
   final List<AdminCategoryNode> categoryTree;
   final Future<ProductOption?> Function(String name, int? categoryId)? onCreate;
   final ImportProductEntryMode? initialEntryMode;
+  final bool canLearnGlobalAlias;
 
   const EditDialog({
     super.key,
@@ -28,6 +29,7 @@ class EditDialog extends StatefulWidget {
     required this.categoryTree,
     this.onCreate,
     this.initialEntryMode,
+    this.canLearnGlobalAlias = false,
   });
 
   @override
@@ -53,6 +55,8 @@ class _EditDialogState extends State<EditDialog> {
   _Destination _destination = _Destination.inventory;
   ImportProductEntryMode _entryMode = ImportProductEntryMode.existing;
   bool _isCreatingProduct = false;
+  bool _learnAlias = false;
+  bool _learnAliasGlobally = false;
 
   // Lokal lista — utökas om nya produkter skapas under dialogen
   late List<ProductOption> _localProducts;
@@ -68,6 +72,8 @@ class _EditDialogState extends State<EditDialog> {
     _productName = widget.current.productName == null
         ? null
         : normalizeProductName(widget.current.productName!);
+    _learnAlias = widget.current.learnAlias;
+    _learnAliasGlobally = widget.current.learnAliasGlobally;
     _destination = widget.current.destination;
     _entryMode = widget.initialEntryMode ??
         (_productId == null
@@ -273,6 +279,8 @@ class _EditDialogState extends State<EditDialog> {
       ItemEdit(
         productId: _productId,
         productName: _productName,
+        learnAlias: _learnAlias,
+        learnAliasGlobally: _learnAlias && widget.canLearnGlobalAlias && _learnAliasGlobally,
         categoryId: _productCategoryId,
         categoryPath: _productCategoryPath,
         categorySource: _productCategorySource,
@@ -358,6 +366,8 @@ class _EditDialogState extends State<EditDialog> {
             else
               _buildCreateProductSection(theme, aiLabel),
             const SizedBox(height: 12),
+            _buildAliasSection(theme, item),
+            const SizedBox(height: 12),
             if (_destination == _Destination.inventory)
               _buildQuantitySection(theme, totalPreview, currentUnit)
             else
@@ -429,6 +439,70 @@ class _EditDialogState extends State<EditDialog> {
         style: const ButtonStyle(visualDensity: VisualDensity.compact),
       );
 
+  Widget _buildAliasSection(ThemeData theme, ParsedReceiptItem item) {
+    final alreadyAliasMatch =
+        _entryMode == ImportProductEntryMode.existing &&
+        _productId != null &&
+        item.matchedVia == 'alias' &&
+        item.matchedProductId == _productId;
+
+    if (alreadyAliasMatch) {
+      return Container(
+        width: double.infinity,
+        padding: const EdgeInsets.all(12),
+        decoration: BoxDecoration(
+          color: theme.colorScheme.primaryContainer.withValues(alpha: 0.45),
+          borderRadius: BorderRadius.circular(12),
+        ),
+        child: Text(
+          'Det här kvittonamnet matchades redan via alias. Ingen ny aliasinlärning behövs.',
+          style: theme.textTheme.bodySmall,
+        ),
+      );
+    }
+
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        CheckboxListTile(
+          contentPadding: EdgeInsets.zero,
+          value: _learnAlias,
+          onChanged: (value) => setState(() {
+            _learnAlias = value ?? false;
+            if (!_learnAlias) _learnAliasGlobally = false;
+          }),
+          title: const Text('Lär detta kvittonamn för framtiden'),
+          subtitle: const Text(
+            'Sparar ett alias så att samma kvittonamn kan matchas direkt vid nästa import.',
+          ),
+          controlAffinity: ListTileControlAffinity.leading,
+        ),
+        if (widget.canLearnGlobalAlias && _learnAlias)
+          Padding(
+            padding: const EdgeInsets.only(left: 12),
+            child: SegmentedButton<bool>(
+              segments: const [
+                ButtonSegment<bool>(
+                  value: false,
+                  label: Text('Privat alias'),
+                  icon: Icon(Icons.lock_outline, size: 16),
+                ),
+                ButtonSegment<bool>(
+                  value: true,
+                  label: Text('Global fallback'),
+                  icon: Icon(Icons.public_outlined, size: 16),
+                ),
+              ],
+              selected: {_learnAliasGlobally},
+              onSelectionChanged: (selection) =>
+                  setState(() => _learnAliasGlobally = selection.first),
+              style: const ButtonStyle(visualDensity: VisualDensity.compact),
+            ),
+          ),
+      ],
+    );
+  }
+
   Widget _buildExistingProductSection(
     ThemeData theme,
     ParsedReceiptItem item,