[Feature] Select All Songs in Manage Songs Dialog

[tungnk123]

Description

Currently, in the Manage Songs Dialog, users have to select songs one by one, which can be time-consuming, especially for large playlists or libraries. Adding a "Select All" option would improve usability and efficiency.

Solution

• Add a "Select All" checkbox at the top of the song selection list.
• When checked, all songs in the list should be selected automatically.
• When unchecked, it should deselect all songs.
• Ensure smooth UI interaction and proper state management when users manually check/uncheck individual songs.

Alternatives

No response

Additional Context

This feature is useful when batch managing songs, such as adding them to playlists or deleting them.

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