Adds a Computer use capability to SKILL.md and a ~250-line
references/COMPUTER-USE.md covering the replicas computer CLI: when to
use computer use vs APIs, why to call the CLI over raw xdotool/scrot,
quickstart, full command reference, common patterns (action/screenshot
loop, coordinate handling from screenshots, recording deliverables,
sharing live with the user via the Desktop dashboard tab), failure
modes, and a table of what's baked into the image vs. lazy-started.
Pairs with the replicas-group/replicas computer-use PR.
Co-Authored-By: Connor Loi <loiconnor8@gmail.com>