feat(ai): add AI trace tracking and admin panel

- Add AiTrace model to Prisma schema with relations to User
- Implement AiTraceService with CRUD operations for AI traces
- Add new admin panel for AI traces with filtering and detail views
- Integrate trace persistence in receipt import flow
- Add API endpoints for listing and retrieving AI traces
- Update Flutter admin UI with new AI tab and navigation
- Add new domain models for AI traces and details
- Add migration for AiTrace table creation

BREAKING CHANGE: None

flutter/lib/features/admin/data/admin_repository.dart

@@ -9,6 +9,8 @@ import '../domain/admin_category_node.dart';
 import '../domain/admin_pantry_item.dart';
 import '../domain/admin_inventory_item.dart';
 import '../domain/admin_product.dart';
+import '../domain/admin_ai_trace.dart';
+import '../domain/admin_ai_trace_detail.dart';
 import '../domain/ai_model_info.dart';
 import '../domain/pending_product.dart';
 import '../domain/receipt_alias.dart';
@@ -145,7 +147,8 @@ class AdminRepository {
           (data['data'] as List<dynamic>?) ??
           const [];
       if (raw.isEmpty && data.isNotEmpty) {
-        debugPrint('[AdminRepository] Unexpected API wrapper shape: ${data.keys}');
+        debugPrint(
+            '[AdminRepository] Unexpected API wrapper shape: ${data.keys}');
       }
     } else {
       raw = const [];
@@ -172,7 +175,8 @@ class AdminRepository {
   Future<UserAdmin> setRecipeSharing(int userId,
           {required bool canShareRecipes}) =>
       _patch(UserApiPaths.setRecipeSharing(userId),
-          body: {'canShareRecipes': canShareRecipes}, parse: UserAdmin.fromJson);
+          body: {'canShareRecipes': canShareRecipes},
+          parse: UserAdmin.fromJson);
 
   Future<void> updateEmail(int userId, String email) =>
       _patchVoid(UserApiPaths.updateEmail(userId), {'email': email});
@@ -194,7 +198,8 @@ class AdminRepository {
         parse: (d) => UserAdmin.fromJson(d as Map<String, dynamic>),
       );
 
-  Future<void> deleteUser(int userId) => _deleteVoid(UserApiPaths.delete(userId));
+  Future<void> deleteUser(int userId) =>
+      _deleteVoid(UserApiPaths.delete(userId));
 
   /// Returns `{ temporaryPassword, to, subject, body }`.
   Future<Map<String, dynamic>> resetPassword(int userId) =>
@@ -203,7 +208,8 @@ class AdminRepository {
   // ── Produkter ──────────────────────────────────────────────────────────────
 
   Future<List<AdminProduct>> listProducts() =>
-      _getList(ProductApiPaths.list, AdminProduct.fromJson, requiresAuth: false);
+      _getList(ProductApiPaths.list, AdminProduct.fromJson,
+          requiresAuth: false);
 
   @Deprecated('Use listProducts(). Kept for temporary compatibility.')
   Future<List<AdminProduct>> listGlobalProducts() => listProducts();
@@ -249,7 +255,8 @@ class AdminRepository {
 
     final list = merged.values.toList();
     list.sort(
-      (a, b) => a.displayName.toLowerCase().compareTo(b.displayName.toLowerCase()),
+      (a, b) =>
+          a.displayName.toLowerCase().compareTo(b.displayName.toLowerCase()),
     );
     _selectableProductsCache = List<AdminProduct>.from(list);
     _selectableProductsCacheAt = now;
@@ -263,7 +270,8 @@ class AdminRepository {
       _getList(ProductApiPaths.pending, PendingProduct.fromJson);
 
   Future<void> setProductStatus(int productId, String status) =>
-      _patchVoid(ProductApiPaths.setStatus(productId), {'status': status}).then((_) {
+      _patchVoid(ProductApiPaths.setStatus(productId), {'status': status})
+          .then((_) {
         _invalidateSelectableProductsCache();
       });
 
@@ -271,14 +279,16 @@ class AdminRepository {
       _post<AdminProduct>(
         ProductApiPaths.promotePrivate(productId),
         body: null,
-        parse: (d) => AdminProduct.fromJson(Map<String, dynamic>.from(d as Map)),
+        parse: (d) =>
+            AdminProduct.fromJson(Map<String, dynamic>.from(d as Map)),
       ).then((value) {
         _invalidateSelectableProductsCache();
         return value;
       });
 
   Future<void> setProductCategory(int productId, {required int? categoryId}) =>
-      _patchVoid(ProductApiPaths.update(productId), {'categoryId': categoryId}).then((_) {
+      _patchVoid(ProductApiPaths.update(productId), {'categoryId': categoryId})
+          .then((_) {
         _invalidateSelectableProductsCache();
       });
 
@@ -301,7 +311,8 @@ class AdminRepository {
         _invalidateSelectableProductsCache();
       });
 
-  Future<void> updateCanonicalNamePrivate(int productId, String canonicalName) =>
+  Future<void> updateCanonicalNamePrivate(
+          int productId, String canonicalName) =>
       _patchVoid(
         ProductApiPaths.canonicalNamePrivate(productId),
         {'canonicalName': canonicalName.trim()},
@@ -336,7 +347,8 @@ class AdminRepository {
 
   int _parseUpdatedCount(dynamic data) {
     if (data is! Map) {
-      debugPrint('[AdminRepository] bulkSetCategory unexpected response type: ${data.runtimeType}');
+      debugPrint(
+          '[AdminRepository] bulkSetCategory unexpected response type: ${data.runtimeType}');
       return 0;
     }
     final map = Map<String, dynamic>.from(data);
@@ -391,8 +403,7 @@ class AdminRepository {
 
   // ── Kategorier ─────────────────────────────────────────────────────────────
 
-  Future<List<AdminCategoryNode>> listCategoryTree() =>
-      _getList(
+  Future<List<AdminCategoryNode>> listCategoryTree() => _getList(
         CategoryApiPaths.tree,
         AdminCategoryNode.fromJson,
         requiresAuth: false,
@@ -404,6 +415,26 @@ class AdminRepository {
   Future<List<AiModelInfo>> listAiModels() =>
       _getList(AiApiPaths.models, AiModelInfo.fromJson);
 
+  Future<AdminAiTraceListResponse> listAiTraces({
+    required AdminAiTraceSource source,
+    int limit = 25,
+    String? cursor,
+    String? period,
+    bool onlyErrors = false,
+  }) =>
+      _getMap(
+        AiApiPaths.traces(
+          source: source.apiValue,
+          limit: limit,
+          cursor: cursor,
+          period: period,
+          onlyErrors: onlyErrors,
+        ),
+      ).then(AdminAiTraceListResponse.fromJson);
+
+  Future<AdminAiTraceDetail> getAiTraceById(String traceId) =>
+      _getMap(AiApiPaths.traceById(traceId)).then(AdminAiTraceDetail.fromJson);
+
   // ── Kvittoalias (admin/global fallback) ───────────────────────────────────
 
   Future<List<ReceiptAlias>> listReceiptAliases() =>
@@ -543,7 +574,8 @@ class AdminRepository {
         if (location != null && location.trim().isNotEmpty)
           'location': location.trim(),
       },
-      parse: (d) => AdminPantryItem.fromJson(Map<String, dynamic>.from(d as Map)),
+      parse: (d) =>
+          AdminPantryItem.fromJson(Map<String, dynamic>.from(d as Map)),
     );
   }
 
@@ -582,6 +614,7 @@ class AdminRepository {
     required int targetInventoryId,
   }) =>
       _getMap(
-        AdminInventoryApiPaths.mergePreview(sourceInventoryId, targetInventoryId),
+        AdminInventoryApiPaths.mergePreview(
+            sourceInventoryId, targetInventoryId),
       );
 }