refactor: convert Control Room views to DataGrid pattern

- Refactor containers_list_page to use shared DataGrid component
- Refactor proxy_hosts_page to use shared DataGrid component
- Add ContainerStatusBadge.fromString() factory for string state values
- Extend CoreApiDataSource to handle raw array API responses
- Simplify data classes (no freezed, just fromJson factories)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

lib/shared/components/data_grid/adapters/core_api_source.dart

@@ -88,28 +88,37 @@ class CoreApiDataSource<T> extends DataGridSource<T> {
       queryParams[limitParam] = limit;
     }
 
-    final response = await dio.get<Map<String, dynamic>>(
+    final response = await dio.get<dynamic>(
       endpoint,
       queryParameters: queryParams,
     );
 
-    final data = response.data!;
+    final responseData = response.data!;
 
     // Handle both paginated and wrapped responses
     List<dynamic> itemsJson;
     int totalCount;
 
-    if (data.containsKey(itemsKey)) {
-      // Paginated response: { items: [...], total: N }
-      itemsJson = data[itemsKey] as List<dynamic>;
-      totalCount = data[totalCountKey] as int? ?? itemsJson.length;
+    if (responseData is List) {
+      // Direct array response: [...]
+      itemsJson = responseData;
+      totalCount = itemsJson.length;
+    } else if (responseData is Map<String, dynamic>) {
+      final data = responseData;
+      if (data.containsKey(itemsKey)) {
+        // Paginated response: { items: [...], total: N }
+        itemsJson = data[itemsKey] as List<dynamic>;
+        totalCount = data[totalCountKey] as int? ?? itemsJson.length;
+      } else {
+        // Try common wrapper patterns: { data: [...] } or { results: [...] }
+        itemsJson = (data['data'] ?? data['results'] ?? []) as List<dynamic>;
+        totalCount = data['count'] as int? ??
+            data['total'] as int? ??
+            data['totalCount'] as int? ??
+            itemsJson.length;
+      }
     } else {
-      // Try common wrapper patterns: { data: [...] } or { results: [...] }
-      itemsJson = (data['data'] ?? data['results'] ?? []) as List<dynamic>;
-      totalCount = data['count'] as int? ??
-          data['total'] as int? ??
-          data['totalCount'] as int? ??
-          itemsJson.length;
+      throw FormatException('Unexpected response type: ${responseData.runtimeType}');
     }
 
     final items = itemsJson