When there is no selection, make `cmd->` (`agent::addSelectionToThread`) use the current line containing the cursor instead of doing nothing. Supports both Zed Agent and Zed Assistant. Works with multiple-cursors and a mix of selections and cursors. Authored by Claude Opus 4.5, tested by me. Release Notes: - agent: Make `agent::addSelectionToThread` (`cmd->`) use the current line of the cursor when there is no selection. --------- Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>