feat(pangolin): Add API authentication to controller deployment

Configure pangolin-kube-controller to authenticate with Pangolin API
using the provided API key.

Changes:
- Add CONFIG_AUTH_HEADER environment variable to controller deployment
- Reference pangolin-controller-api-key secret (not yet created)
- Secret will contain Bearer token for API authentication

BLOCKED: Requires manual secret sealing step before deployment.

To complete this deployment, run on a machine with cluster access:

kubectl create secret generic pangolin-controller-api-key \
  --namespace=pangolin \
  --from-literal=auth-header="Bearer 5qid06u9j325kpk.ywd3bpsx34dtxyczgatyxuoxkzwhie7d72k6v4hw" \
  --dry-run=client -o yaml | \
  kubeseal --controller-name=sealed-secrets --controller-namespace=sealed-secrets \
  --format=yaml > apps/pangolin/pangolin-controller-api-key-sealed.yaml

Then commit the sealed secret and push both files.

Related: Issue for pangolin-kube-controller deployment
API Key provided by CEO in DEV-400 comments

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/pangolin/pangolin-controller-deployment.yaml

@@ -26,6 +26,12 @@ spec:
           envFrom:
             - configMapRef:
                 name: pangolin-controller-config
+          env:
+            - name: CONFIG_AUTH_HEADER
+              valueFrom:
+                secretKeyRef:
+                  name: pangolin-controller-api-key
+                  key: auth-header
           ports:
             - name: metrics
               containerPort: 9090