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/daily/DailyCheckboxSortable.tsx

@@ -0,0 +1,78 @@
+'use client';
+
+import { useSortable } from '@dnd-kit/sortable';
+import { CSS } from '@dnd-kit/utilities';
+import { DailyCheckbox, DailyCheckboxType } from '@/lib/types';
+import { DailyCheckboxItem } from './DailyCheckboxItem';
+
+interface DailyCheckboxSortableProps {
+  checkbox: DailyCheckbox;
+  onToggle: (checkboxId: string) => Promise<void>;
+  onUpdate: (checkboxId: string, text: string, type: DailyCheckboxType, taskId?: string) => Promise<void>;
+  onDelete: (checkboxId: string) => Promise<void>;
+  saving?: boolean;
+}
+
+export function DailyCheckboxSortable({
+  checkbox,
+  onToggle,
+  onUpdate,
+  onDelete,
+  saving = false
+}: DailyCheckboxSortableProps) {
+  const {
+    attributes,
+    listeners,
+    setNodeRef,
+    transform,
+    transition,
+    isDragging,
+  } = useSortable({
+    id: checkbox.id,
+  });
+
+  const style = {
+    transform: CSS.Transform.toString(transform),
+    transition,
+    opacity: isDragging ? 0.5 : 1,
+  };
+
+  return (
+    <div
+      ref={setNodeRef}
+      style={style}
+      className={`
+        ${isDragging ? 'z-50' : 'z-0'}
+        ${isDragging ? 'shadow-lg' : ''}
+        transition-shadow duration-200
+      `}
+    >
+      <div className="relative group">
+        {/* Handle de drag */}
+        <div 
+          {...attributes} 
+          {...listeners}
+          className="absolute left-0 top-0 bottom-0 w-3 cursor-grab active:cursor-grabbing flex items-center justify-center opacity-0 group-hover:opacity-100 transition-opacity"
+          title="Glisser pour réorganiser"
+        >
+          <div className="w-1.5 h-6 flex flex-col justify-center gap-0.5">
+            <div className="w-full h-0.5 bg-[var(--muted-foreground)] rounded"></div>
+            <div className="w-full h-0.5 bg-[var(--muted-foreground)] rounded"></div>
+            <div className="w-full h-0.5 bg-[var(--muted-foreground)] rounded"></div>
+          </div>
+        </div>
+        
+        {/* Checkbox item avec padding left pour le handle */}
+        <div className="pl-4">
+          <DailyCheckboxItem
+            checkbox={checkbox}
+            onToggle={onToggle}
+            onUpdate={onUpdate}
+            onDelete={onDelete}
+            saving={saving}
+          />
+        </div>
+      </div>
+    </div>
+  );
+}