[FEAT] Added group hydration

lib/src/form/src/controller.dart

@@ -106,17 +106,6 @@ class AstromicFormController {
     return node<T>(id).value;
   }
 
-  /// Safely attempts to retrieve a value, returning `null` if the node is missing or of a different type.
-  // T? tryGet<T>(String id) {
-  //   if (_nodes.containsKey(id)) {
-  //     final n = _nodes[id];
-  //     if (n is AstromicFieldNode<T>) {
-  //       return n.value;
-  //     }
-  //   }
-  //   return null;
-  // }
-
   T? tryGet<T>(String id) {
     final n = _nodes[id];
     if (n == null) return null;
@@ -131,7 +120,7 @@ class AstromicFormController {
 
     // Fallback for null-safety: if T is nullable and value is null
     if (value == null && _isNullable<T>()) {
-       return null;
+      return null;
     }
 
     return null;
@@ -276,6 +265,38 @@ class AstromicFormController {
     }).toList();
   }
 
+  /// Hydrates a dynamic group with a list of data maps.
+  ///
+  /// Each map in [data] represents one instance of the group.
+  /// This method generates a UUID for each map and populates the fields.
+  void hydrateGroup(String groupId, List<Map<String, dynamic>> data, {String? parentUuid}) {
+    // 1. Clear existing manifest for this group/parent context to prevent duplication
+    final manifest = getManifest(groupId, parentUuid);
+    manifest.value = [];
+
+    // 2. Iterate through each data object (row)
+    for (final rowData in data) {
+      // 3. Add a fresh instance (this generates the UUID and registers field nodes)
+      final String newUuid = addGroupInstance(
+        groupId,
+        parentUuid: parentUuid,
+        initialData: rowData,
+      );
+
+      // 4. Handle Nested Subgroups (Recursion)
+      final def = _groupDefs[groupId];
+      if (def != null && def.subGroups.isNotEmpty) {
+        for (final subId in def.subGroups) {
+          if (rowData.containsKey(subId) && rowData[subId] is List) {
+            final List<Map<String, dynamic>> subData = List<Map<String, dynamic>>.from(rowData[subId]);
+
+            hydrateGroup(subId, subData, parentUuid: newUuid);
+          }
+        }
+      }
+    }
+  }
+
   /// Retrieves the schema definition for a registered group.
   AstromicFormGroupDefinition? getGroupDef(String id) => _groupDefs[id];