Improve Memoria and OpenClaw onboarding installers

[randomradio]

Summary

• make scripts/install.sh a friendlier Memoria + MatrixOne readiness entrypoint, including current mo_ctl installer handling and system dependency checks
• make the OpenClaw plugin installer able to install/check OpenClaw, Memoria, MatrixOne, and related system dependencies with clearer step-by-step guidance
• update README guidance for the new onboarding paths

Validation

• syntax-checked scripts/install.sh and plugins/openclaw/scripts/install-openclaw-memoria.sh
• validated the root installer in an Ubuntu 24.04 Docker container against a reachable MatrixOne target (host.docker.internal:6001)
• validated the OpenClaw plugin installer in an Ubuntu 24.04 Docker container through verify_plugin_install.mjs, which returned ok: true and completed embedded stats / ltm list deep checks
• fixed two real cold-start gaps discovered during container validation: the current mo_ctl installer URL moved to deploy/local/install.sh, and automatic openclaw installation on clean Ubuntu also needed git