Replaces the queue rows' up/down arrow buttons with a drag handle (arrow
keys still work on the focused handle). Also prunes optimistic queued
messages once the projection holds them: keying the prune on turn items
alone left a phantom clock row behind whenever a queued run was removed
or steered before it ever started.

Built by Claude Fable 5 on Claude Code.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>