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/services/api.ts

@@ -1071,6 +1071,10 @@ export interface Task {
   word_count: number;
   meta_title?: string | null;
   meta_description?: string | null;
+  primary_keyword?: string | null;
+  secondary_keywords?: string[] | null;
+  tags?: string[] | null;
+  categories?: string[] | null;
   assigned_post_id?: number | null;
   post_url?: string | null;
   created_at: string;