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/notifications.config.ts

@@ -37,7 +37,7 @@ export const pageNotifications: Record<string, PageNotificationConfig> = {
     message: 'Track and manage your content writing tasks and deadlines.',
     showLink: false,
   },
-  '/writer/drafts': {
+  '/writer/content': {
     variant: 'info',
     title: 'Drafts',
     message: 'Review and edit your content drafts before publishing.',