fix: use nodeenv lts instead of pinned node 22

nodeenv doesn't support major-only version specifiers. Use lts
which resolves to the latest LTS release.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

setup/install-node.sh

@@ -19,7 +19,7 @@ fi
 
 if command -v uvx >/dev/null 2>&1; then
   echo "STEP: uvx-nodeenv"
-  uvx nodeenv -n 22 ~/node
+  uvx nodeenv -n lts ~/node
   mkdir -p ~/.local/bin
   ln -sf ~/node/bin/node ~/.local/bin/node
   ln -sf ~/node/bin/npm ~/.local/bin/npm