Add new fields to TasksSerializer and enhance auto_generate_content_task with detailed step tracking

- Updated TasksSerializer to include 'primary_keyword', 'secondary_keywords', 'tags', and 'categories'.
- Enhanced auto_generate_content_task to track progress with detailed steps, including initialization, preparation, AI call, parsing, and saving.
- Updated progress modal to reflect new phases and improved animation for smoother user experience.
- Adjusted routing and configuration for content and drafts pages in the frontend.

frontend/src/config/pages/bulk-action-modal.config.ts

@@ -99,7 +99,7 @@ export const bulkActionModalConfigs: Record<string, BulkActionModalConfig> = {
       ],
     },
   },
-  '/writer/drafts': {
+  '/writer/content': {
     export: {
       title: 'Export Selected Drafts',
       message: (count: number) => `You are about to export ${count} selected draft${count !== 1 ? 's' : ''}. The export will be downloaded as a CSV file.`,