fix: use custom WordPress image with wp-cli pre-installed

Adds a Dockerfile extending wordpress:latest to include wp-cli at
/usr/local/bin/wp. Required for sync-whitepapers.py to manage content
via kubectl exec without manual installation after each pod restart.

servers/legion/k8s/harmonic-wordpress/Dockerfile

@@ -0,0 +1,6 @@
+FROM wordpress:latest
+
+# Install wp-cli so sync-whitepapers.py can manage content via kubectl exec
+RUN curl -sL https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar \
+      -o /usr/local/bin/wp \
+    && chmod +x /usr/local/bin/wp

servers/legion/k8s/harmonic-wordpress/deployment.yaml

@@ -96,7 +96,7 @@ spec:
     spec:
       containers:
         - name: wordpress
-          image: wordpress:latest
+          image: registry.neuralplatform.ai/harmonic-wordpress:latest
           ports:
             - containerPort: 80
           env: