Upgrade `rigdoctor monitor` from a basic redraw to a stdlib curses dashboard
(tui.py): current / session-min / session-max per sensor, grouped by subsystem,
with temperature & utilization color bands (GPU-lost flagged red). q quits,
r resets min/max. Plain full-screen redraw fallback on a non-TTY (--plain forces
it). Pure track()/band() helpers are unit-tested; curses path verified in a pty.
Completes the Monitoring bundle (M2 + M8).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
