feat(ai): enhance AI trace warnings with product context

- Added `productName` field to `AdminAiWarning` to include product context in warnings
- Updated `collectWarnings` to extract and include `rawName` as `productName` in AI trace warnings
- Added `signals` field to `FlyerParseItem` type for detailed product signals
- Enhanced Flutter admin panel to display product names in AI trace warnings
- Added new `AdminAiTraceResponse` DTO for AI trace data structure

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

@@ -139,7 +139,8 @@ class _AdminAiPanelState extends ConsumerState<AdminAiPanel> {
 
   String _formatWarningLine(AdminAiWarning warning) {
     final rowSuffix = warning.itemIndex == null ? '' : ' (rad ${warning.itemIndex})';
-    return '[${warning.severity}] ${warning.title}$rowSuffix: ${warning.message}';
+    final productSuffix = warning.productName != null ? ' (${warning.productName})' : '';
+    return '[${warning.severity}] ${warning.title}$rowSuffix$productSuffix: ${warning.message}';
   }
 
   String _buildErrorReport({
@@ -685,11 +686,16 @@ class _WarningsCard extends StatelessWidget {
                         warning.location!,
                         style: theme.textTheme.bodySmall,
                       ),
-                    if (warning.itemIndex != null)
-                      Text(
-                        'Rad: ${warning.itemIndex}',
-                        style: theme.textTheme.bodySmall,
-                      ),
+                     if (warning.itemIndex != null)
+                       Text(
+                         'Rad: ${warning.itemIndex}',
+                         style: theme.textTheme.bodySmall,
+                       ),
+                     if (warning.productName != null)
+                       Text(
+                         'Produkt: ${warning.productName}',
+                         style: theme.textTheme.bodySmall,
+                       ),
                   ],
                 ),
                 trailing: IconButton(