feat: refactor daily task management with new pending tasks section

- Added `PendingTasksSection` to `DailyPageClient` for displaying uncompleted tasks.
- Implemented `getPendingCheckboxes` method in `DailyClient` and `DailyService` to fetch pending tasks.
- Introduced `getDaysAgo` utility function for calculating elapsed days since a date.
- Updated `TODO.md` to reflect the new task management features and adjustments.
- Cleaned up and organized folder structure to align with Next.js 13+ best practices.

src/app/api/daily/checkboxes/[id]/archive/route.ts

@@ -0,0 +1,28 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { dailyService } from '@/services/daily';
+
+export async function PATCH(
+  request: NextRequest,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  try {
+    const { id: checkboxId } = await params;
+    
+    if (!checkboxId) {
+      return NextResponse.json(
+        { error: 'Checkbox ID is required' },
+        { status: 400 }
+      );
+    }
+
+    const archivedCheckbox = await dailyService.archiveCheckbox(checkboxId);
+
+    return NextResponse.json(archivedCheckbox);
+  } catch (error) {
+    console.error('Error archiving checkbox:', error);
+    return NextResponse.json(
+      { error: 'Failed to archive checkbox' },
+      { status: 500 }
+    );
+  }
+}