feat: add an updates card showing nvtable's package table

Moves the nvchecker/nvtable table the login shell printed onto the
dashboard, as a wide card at the bottom centre. bin/updates-sample.sh
caches `nvtable -C -E` every ten minutes and starts nvchecker, fully
detached, at most every 30 minutes. The widget parses the cache and
colours it in the board's language: installed behind upstream is
critical, a shipped .info behind is a warning, with nvtable's status
dots per row and a legend on the bottom line. The mouse wheel scrolls
rows that do not fit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions