With ECO_NO_X=1 or without X, the terminal tweak's detector recording
now plots as text (uniplot) just above the status line, redrawn in place
as points come in -- same layout as the Qt plot: detector(s) vs position
for one adjustable, detectors over positions vs step for several.
New eco.utilities.termplot, the wrapper planned in docs/terminal_plots.md:
panel_stack() for stacked plots over a shared x, and LiveRegion /
LivePlotter for in-place redraws that coexist with a '\r' status line
(prints a fresh copy if other output scrolled in between).
