feat(installer): install additional npm packages for pi-agent

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.

installer/pi-agent.sh

@@ -15,4 +15,9 @@ if [[ -x "$(command -v pass)" ]]; then
     pass show agent/pi/agent/auth.json > ~/.pi/agent/auth.json
 fi
 
+pi install npm:pi-lens
+pi install npm:@gotgenes/pi-permission-system
+pi install npm:pi-native-search
+pi install npm:pi-subagents
+pi install npm:context-mode