neuron-web: drop unused registry-pull-secret

The registry currently allows anonymous cluster-internal pulls so the
imagePullSecrets reference was failing the externalsecret reconcile
(secret/data/mudcraft has no registry creds for this app). Pod was
pulling fine anyway. If the registry later gets locked down, add a
proper externalsecret using the path from secret/data/<app> instead of
borrowing mudcraft's.

servers/legion/k8s/neuron-technologies/web/deployment.yaml

@@ -22,8 +22,10 @@ spec:
         app: neuron-web
         env: stage
     spec:
-      imagePullSecrets:
-        - name: registry-pull-secret
+      # The registry currently allows anonymous reads from the cluster; if we
+      # later flip it to require auth, add a registry-pull-secret here that
+      # ESO populates from Vault. See the mudcraft externalsecret-registry
+      # for the pattern.
       containers:
         - name: neuron-web
           image: registry.neuralplatform.ai/neuron-web:dev-dfe41234