Motivation

• Improve history statistics readability by grouping stream entries by date when sorted by last played.
• Introduce a dedicated DATE_HEADER local item type so headers can be rendered as full-width list items.

Description

• Added LocalItem.LocalItemType.DATE_HEADER and a new data class DateHeaderItem that carries a LocalDate value and implements LocalItem.
• Extended LocalItemListAdapter with a new holder type DATE_HEADER_HOLDER_TYPE, a DateHeaderHolder, view inflation of R.layout.list_date_header_item, binding logic for DateHeaderItem, and span lookup so headers span all columns.
• Created layout list_date_header_item.xml for the date header TextView and added required imports and resources to the adapter.
• Updated StatisticsPlaylistFragment.processResult to insert DateHeaderItem entries before each date group when StatisticSortMode is LAST_PLAYED, and adjusted getPlayQueueStartingAt to compute the correct play index while skipping header items.
• Removed date formatting from the statistic stream detail line in LocalStatisticStreamItemHolder so date rendering is handled by the new header view.

Testing

• Built the app with ./gradlew assembleDebug which completed successfully.
• Ran unit tests with ./gradlew test which completed successfully.

Codex Task