feat: proširi prikaz dizalice i vlasnika u zadacima

Dodaj detalje dizalice (proizvođač, model i SN) te vlasnika u modal radnog zadatka i kalendar zadataka, uz zajednički frontend helper za DRY prikaz.

Proširi Task API serializer dodatnim poljima za prikaz dizalice/vlasnika i ažuriraj testove serializera za nova izlazna polja.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/modules/task_management/serializers.py

@@ -86,6 +86,11 @@ class TaskSerializer(serializers.ModelSerializer):
     assigned_to_name = serializers.SerializerMethodField()
     work_order_label = serializers.SerializerMethodField()
     vehicle_registration = serializers.SerializerMethodField()
+    vehicle_make = serializers.SerializerMethodField()
+    vehicle_model = serializers.SerializerMethodField()
+    vehicle_owner_name = serializers.SerializerMethodField()
+    vehicle_asset_type = serializers.SerializerMethodField()
+    crane_serial_number = serializers.SerializerMethodField()
     template_id = serializers.UUIDField(write_only=True, required=False, allow_null=True)
     auto_close_work_order = serializers.BooleanField(write_only=True, required=False)
 
@@ -94,7 +99,8 @@ class TaskSerializer(serializers.ModelSerializer):
         fields = [
             'id', 'title', 'description', 'status',
             'assigned_to', 'assigned_to_name',
-            'vehicle', 'vehicle_registration',
+            'vehicle', 'vehicle_registration', 'vehicle_make', 'vehicle_model',
+            'vehicle_owner_name', 'vehicle_asset_type', 'crane_serial_number',
             'work_order', 'work_order_label',
             'scheduled_date',
             'template_id', 'auto_close_work_order',
@@ -180,3 +186,28 @@ class TaskSerializer(serializers.ModelSerializer):
         if not obj.vehicle_id:
             return None
         return obj.vehicle.registration_number
+
+    def get_vehicle_make(self, obj):
+        if not obj.vehicle_id:
+            return None
+        return obj.vehicle.make or None
+
+    def get_vehicle_model(self, obj):
+        if not obj.vehicle_id:
+            return None
+        return obj.vehicle.model or None
+
+    def get_vehicle_owner_name(self, obj):
+        if not obj.vehicle_id or not obj.vehicle.client_id:
+            return None
+        return obj.vehicle.client.name
+
+    def get_vehicle_asset_type(self, obj):
+        if not obj.vehicle_id:
+            return None
+        return obj.vehicle.asset_type
+
+    def get_crane_serial_number(self, obj):
+        if not obj.vehicle_id:
+            return None
+        return obj.vehicle.crane_serial_number or None