feat: add clsx and tailwind-merge dependencies, enhance Kanban components

- Added `clsx` and `tailwind-merge` to `package.json` and `package-lock.json` for improved class management and utility merging.
- Updated `Column` and `TaskCard` components to utilize new UI components (`Card`, `Badge`) for a more cohesive design.
- Refactored styles in `Header` and Kanban components to align with the new design system.
- Marked several tasks as completed in `TODO.md` reflecting progress on UI enhancements.

tsconfig.json

@@ -21,7 +21,8 @@
     "paths": {
       "@/*": ["./src/*"],
       "@/services/*": ["./services/*"],
-      "@/lib/*": ["./lib/*"]
+      "@/lib/*": ["./lib/*"],
+      "@/components/*": ["./components/*"]
     }
   },
   "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],