refactor(hooks): extract shared attendance data fetching logic into custom hook

[Vishal-770]

Description

Currently, src/pages-mobile/dashboard/attendance/[classId].tsx and src/pages-desktop/dashboard/attendance/[classId].tsx duplicate data fetching, local storage hydration, offline handling, and manual retry states.

Tasks

• Create src/hooks/use-attendance-detail.ts hook.
• Move cache loading, network fetch, and manual retry state into the hook.
• Refactor both Mobile and Desktop attendance detail pages to consume the hook.