fix(bootstrap): safe uninstall, add license, CI, and docs

- Fix uninstall to only remove own files (farmer/sprout can coexist)
- Add systemctl daemon-reload after removing unit files
- Suppress userdel error if user doesn't exist
- Add 0BSD LICENSE (matches gogrlx/grlx)
- Add GitHub Actions CI workflow (shellcheck)
- Expand README: non-interactive install, uninstall docs, arch list, badges

latest/sprout

@@ -72,7 +72,14 @@ EOF
 else
 	systemctl disable --now grlx-sprout
 	rm -f /etc/systemd/system/grlx-sprout.service
+	systemctl daemon-reload
 	rm -f /usr/local/bin/grlx-sprout
-	rm -rf /etc/grlx
-    rm -rf /var/cache/grlx
+	rm -f /etc/grlx/sprout
+	rm -rf /etc/grlx/pki/sprout
+	# Only remove /etc/grlx if empty (farmer config may still exist)
+	rmdir /etc/grlx/pki 2>/dev/null || true
+	rmdir /etc/grlx 2>/dev/null || true
+	rm -rf /var/cache/grlx/sprout
+	# Only remove /var/cache/grlx if empty
+	rmdir /var/cache/grlx 2>/dev/null || true
 fi