Refactor content handling in GenerateContentFunction and update related models and serializers

- Enhanced GenerateContentFunction to save content in a dedicated Content model, separating it from the Tasks model.
- Updated Tasks model to remove SEO-related fields, now managed in the Content model.
- Modified TasksSerializer to include new content fields and adjusted the API to reflect these changes.
- Improved the auto_generate_content_task method to utilize the new save_output method for better content management.
- Updated frontend components to display new content structure and metadata effectively.

frontend/src/components/common/ProgressModal.tsx

@@ -169,33 +169,6 @@ export default function ProgressModal({
           />
         </div>
 
-        {/* Details */}
-        {details && (
-          <div className="mb-6 space-y-2">
-            {details.currentItem && (
-              <div className="text-sm text-gray-700 dark:text-gray-300">
-                <span className="font-medium">Current:</span>{' '}
-                <span className="text-gray-600 dark:text-gray-400">
-                  {details.currentItem}
-                </span>
-              </div>
-            )}
-            {details.total > 0 && (
-              <div className="text-sm text-gray-700 dark:text-gray-300">
-                <span className="font-medium">Progress:</span>{' '}
-                <span className="text-gray-600 dark:text-gray-400">
-                  {details.current} of {details.total} completed
-                </span>
-              </div>
-            )}
-            {details.phase && (
-              <div className="text-xs text-gray-500 dark:text-gray-500">
-                Phase: {details.phase}
-              </div>
-            )}
-          </div>
-        )}
-
         {/* Function ID and Task ID (for debugging) */}
         {(fullFunctionId || taskId) && import.meta.env.DEV && (
           <div className="mb-4 space-y-1 text-xs text-gray-400 dark:text-gray-600">