feat(bin): refresh omo skills from upstream daily on flowstate-remote

skills-update re-vendors impeccable (newest skill-v* release) and
web-design-guidelines the way the skills README describes, then commits
only .config/omo/skills and pushes when main was level with origin/main.
It also syncs the machine-local vercel-react-best-practices, docx, pdf,
pptx, xlsx and skill-creator copies from vercel-labs/agent-skills and
anthropics/skills. A failed update keeps the previous copy and exits
non-zero. skills-update --install-timer writes and enables the daily
systemd user timer.

It is Linux only, so setup-mac.sh does not link it.

setup-mac.sh

@@ -198,7 +198,7 @@ step_links() {
         name=${script##*/}
         case $name in
             pbcopy | pbpaste) continue ;; # OSC 52 clipboard shims for headless servers
-            impeccable-browser) continue ;; # Linux-only browser shim for flowstate-remote
+            impeccable-browser | skills-update) continue ;; # Linux-only tools for flowstate-remote
         esac
         if [[ -x $script ]]; then link ".local/bin/$name" ".local/bin/$name"; fi
     done