This commit adds new npm package installations to the pi-agent installer script, enhancing its capabilities with pi-lens, pi-permission-system, pi-native-search, pi-subagents, and context-mode.
Adds a shell script that installs the @earendil-works/pi-coding-agent
and pi-acp npm packages globally if the `pi` command is not found.
Uses paru to install Node.js and npm on Arch-based systems when needed.