[daviddanialy]

Summary

You can now click and drag the transcript scrollbar in kit tui.

• A left press on the scrollbar scrolls instead of starting a text selection.
• Dragging the thumb keeps the grabbed cell under the pointer. scrollbar_thumb reproduces ratatui's thumb geometry, and the drag picks the smallest scroll offset that renders the thumb at the target row, so grabbing the thumb doesn't make it jump.
• A press on the track centers the thumb there. Dragging to the last thumb row turns auto-follow back on.
• Rows past either end clamp, so the drag keeps working off the bar. Motion that leaves the view unchanged doesn't request a redraw.
• Dialogs drawn over the transcript (sessions, model, effort, file picker, command popup) take the press, not the bar.
• In a focused child view, drags and releases that cross into the agent roster still reach the child.
• A drag isn't cancelled by streaming layout changes. A lost release (e.g. letting go outside the terminal) clears on the next press.
• The docs list the scrollbar as a scroll control.

Testing

• mise run lint
• mise run test -- --lib tui:: (628 passed)
• New app test: thumb grab without a jump, track press, clamping, follow, redraw only on change, a layout change mid-drag, and a lost release.
• New ui test: renders through draw and checks that the drawn thumb lands under the pointer after each drag.
• The demo was recorded with VHS. VHS can't send mouse input, so a small pty wrapper injected SGR mouse drag sequences on the scrollbar column.

🤖 Generated with Claude Code

[kit-code-agent]

Grabbing the thumb can change the transcript offset without pointer movement and unexpectedly resume auto-follow. A full-track thumb also forces the transcript to the top and disables following.

_{Took 13 min}

[kit-code-agent]

Dragging past the bottom does not restore auto-follow when a non-bottom scroll offset already renders the thumb at its last row.

_{Took 5 min 54 sec}

[kit-code-agent]

No issues found. The changes look good to merge.

_{Took 8 min 53 sec}