What would you like to be added?

Support batch deletion of sessions. Users should be able to select multiple sessions and delete them all at once, instead of deleting them one by one.

This feature should be available in:

• CLI: In the session picker (opened via `/delete`), allow selecting multiple sessions before confirming deletion.

Why is this needed?

Currently, sessions can only be deleted one at a time. When users accumulate many old sessions and want to clean them up, they must delete each session individually, which is tedious and time-consuming.

Batch deletion is a common UX pattern in session/history management interfaces and would significantly improve the user experience when managing accumulated chat history.

Additional context

Current implementation:

• `SessionService.removeSession()` in `packages/core/src/services/sessionService.ts` deletes a single session.
• CLI `/delete` command (`packages/cli/src/ui/commands/deleteCommand.ts`) opens a dialog for single session selection.

No batch/bulk delete functionality currently exists in the codebase.