refactor: rename custom components from shannon-* to hightower-*

Renames API server, worker jobs, credentials secret, and workspaces
PVC to use the hightower prefix. Upstream Shannon names (namespace,
Temporal service, package imports, .shannon/ dir) are unchanged.

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

apps/cli/infra/k8s/router.yaml

@@ -31,7 +31,7 @@ spec:
             - containerPort: 3456
           envFrom:
             - secretRef:
-                name: shannon-credentials
+                name: hightower-credentials
           env:
             - name: HOST
               value: "0.0.0.0"

apps/cli/infra/k8s/workspaces-pvc.yaml

@@ -1,7 +1,7 @@
 apiVersion: v1
 kind: PersistentVolumeClaim
 metadata:
-  name: shannon-workspaces
+  name: hightower-workspaces
   namespace: shannon
 spec:
   accessModes: