Refactor keyword handling: Replace 'intent' with 'country' across backend and frontend

- Updated AutomationService to include estimated_word_count.
- Increased stage_1_batch_size from 20 to 50 in AutomationViewSet.
- Changed Keywords model to replace 'intent' property with 'country'.
- Adjusted ClusteringService to allow a maximum of 50 keywords for clustering.
- Modified admin and management commands to remove 'intent' and use 'country' instead.
- Updated serializers to reflect the change from 'intent' to 'country'.
- Adjusted views and filters to use 'country' instead of 'intent'.
- Updated frontend forms, filters, and pages to replace 'intent' with 'country'.
- Added migration to remove 'intent' field and add 'country' field to SeedKeyword model.

backend/igny8_core/business/automation/views.py

@@ -82,7 +82,7 @@ class AutomationViewSet(viewsets.ViewSet):
             "is_enabled": true,
             "frequency": "daily",
             "scheduled_time": "02:00",
-            "stage_1_batch_size": 20,
+            "stage_1_batch_size": 50,
             ...
         }
         """