feat: implement drag-and-drop reordering for daily checkboxes

- Added DnD functionality to `DailySection` for reordering checkboxes using `@dnd-kit/core` and `@dnd-kit/sortable`.
- Introduced `onReorderCheckboxes` prop to handle server updates after reordering.
- Updated `useDaily` hook to streamline error handling during reordering.
- Cleaned up `Header` component by removing unnecessary syncing text.
- Adjusted `DailyPageClient` to pass reorder function to `DailySection`.

components/ui/Header.tsx

@@ -51,7 +51,7 @@ export function Header({ title = "TowerControl", subtitle = "Task Management", s
                   {title}
                 </h1>
                 <p className="text-[var(--muted-foreground)] mt-1 font-mono text-sm">
-                  {subtitle} {syncing && '• Synchronisation...'}
+                  {subtitle}
                 </p>
               </div>
             </div>