Feature Request: Allow resizing the drop-down terminal height by dragging its bottom edge

Context: Similar to how Windows Terminal allows it, I'd like to click and drag the bottom bar of the drop-down terminal up or down to adjust its height. This is especially useful when running commands with long output, as you can temporarily expand the terminal to see more without leaving the drop-down view.

Current behavior: The drop-down terminal has a fixed height.
Expected behavior: A draggable resize handle on the bottom edge.

No file or test is named. Start by locating the drop-down terminal's fixed-height behavior and its existing UI event handling, then trace how the bottom edge is represented. Done means the bottom edge can be dragged up or down to resize the drop-down terminal without leaving the drop-down view.

Written by the indexing model from the issue text.