refactor: load app config from JSON fixture

- Loads app config from app_config.json
- Uses AppConfig.fromJson for parsing
- Inits repository with parsed config

Author: fulleni

lib/src/fixtures/app_config.json

@@ -0,0 +1,72 @@
+{
+  "id": "app_config",
+  "user_preference_limits": {
+    "guest_followed_items_limit": 5,
+    "guest_saved_headlines_limit": 10,
+    "authenticated_followed_items_limit": 15,
+    "authenticated_saved_headlines_limit": 30,
+    "premium_followed_items_limit": 30,
+    "premium_saved_headlines_limit": 100
+  },
+  "ad_config": {
+    "guest_ad_frequency": 5,
+    "guest_ad_placement_interval": 3,
+    "authenticated_ad_frequency": 10,
+    "authenticated_ad_placement_interval": 5,
+    "premium_ad_frequency": 0,
+    "premium_ad_placement_interval": 0
+  },
+  "engagement_rules": [
+    {
+      "template_type": "rate-app",
+      "user_roles": ["standard_user"],
+      "min_days_since_account_creation": 7,
+      "max_times_to_show": 1,
+      "min_days_since_last_shown": 30,
+      "placement": {
+        "after_primary_item_index": 5,
+        "min_primary_items_required": 10
+      }
+    },
+    {
+      "template_type": "link-account",
+      "user_roles": ["guest_user"],
+      "min_days_since_account_creation": 3,
+      "max_times_to_show": 3,
+      "min_days_since_last_shown": 7,
+      "placement": {
+        "after_primary_item_index": 3,
+        "min_primary_items_required": 5
+      }
+    },
+    {
+      "template_type": "upgrade-to-premium",
+      "user_roles": ["standard_user"],
+      "min_days_since_account_creation": 14,
+      "max_times_to_show": 2,
+      "min_days_since_last_shown": 15,
+      "placement": {
+        "relative_position": "middle",
+        "min_primary_items_required": 10
+      }
+    }
+  ],
+  "suggestion_rules": [
+    {
+      "template_type": "categories-to-follow",
+      "user_roles": ["guest_user", "standard_user"],
+      "placement": {
+        "after_primary_item_index": 7,
+        "min_primary_items_required": 10
+      }
+    },
+    {
+      "template_type": "sources-to-follow",
+      "user_roles": ["standard_user"],
+      "placement": {
+        "relative_position": "end_quarter",
+        "min_primary_items_required": 15
+      }
+    }
+  ]
+}

routes/_middleware.dart

@@ -184,12 +184,13 @@ HtDataRepository<UserContentPreferences>
 
 HtDataRepository<AppConfig> _createAppConfigRepository() {
   print('Initializing AppConfig Repository...');
-  // AppConfig should have a single instance, potentially loaded from a file
-  // or created with defaults if not found. For in-memory, we can create a
-  // default instance.
+  final fixtureData = _loadFixtureSync('app_config.json');
+  if (fixtureData.isEmpty) {
+    throw Exception('Failed to load app_config.json fixture or it is empty.');
+  }
   final initialData = [
-    const AppConfig(id: 'app_config'), // Default config
-  ];
+    AppConfig.fromJson(fixtureData.first),
+  ]; // Assuming one config
   final client = HtDataInMemoryClient<AppConfig>(
     toJson: (i) => i.toJson(),
     getId: (i) => i.id,