feat: scaffold conky_widget desktop monitor

Conky (X11 + Lua + Cairo) desktop widget with three clickable tabs
(Red / Sistema / Docker) rendered entirely with Cairo:

- Red: live down/up speed for enp5s0, 60s history graph, active
  connections count, totals, and launcher buttons for Wireshark,
  ntopng and nethogs (with notify-send fallback when missing).
- Sistema: total CPU + per-core bars, RAM, swap, root disk usage,
  temperature, load average and uptime.
- Docker: running/total container count and active container names
  (read without sudo).

Includes install.sh (symlink into ~/.config/conky + XFCE autostart),
launch.sh (tool launcher with missing-binary fallback) and app.md
with e2e_checks. Positioned top-right of the primary monitor
(xinerama_head 0), configurable.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

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+*.log