Add Node.js profile.d config and pnpm package manager

- config/files/etc/profile.d/nodejs.sh: sets NPM_CONFIG_PREFIX and
  PATH so user-level npm global installs go to ~/.npm-global (no sudo)
- Install pnpm from Fedora repos (dnf5) alongside nodejs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: iwillig

Containerfile.d/060-languages.containerfile

@@ -1,6 +1,6 @@
 # Pi coding agent — use dnf5 (not rpm-ostree) so nodejs is immediately available
 # for the subsequent npm call within the same RUN step
-RUN dnf5 install -y nodejs && \
+RUN dnf5 install -y nodejs pnpm && \
     dnf5 clean all && \
     npm install -g --prefix /usr --ignore-scripts @earendil-works/pi-coding-agent && \
     ostree container commit

config/files/etc/profile.d/nodejs.sh

@@ -0,0 +1,4 @@
+if command -v node >/dev/null 2>&1; then
+    export NPM_CONFIG_PREFIX="${HOME}/.npm-global"
+    export PATH="${HOME}/.npm-global/bin:${PATH}"
+fi