refactor: rename all custom K8s components to hightower

Namespace, Temporal, router, PVCs, labels, and GHCR API image all
renamed from shannon-* to hightower-*. Upstream references preserved:
worker image (ghcr.io/farhoodliquor/shannon), .shannon/ dirs,
@shannon/worker package imports.

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

apps/api/infra/base/deployment.yaml

@@ -2,7 +2,7 @@ apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: hightower-api
-  namespace: shannon
+  namespace: hightower
   labels:
     app: hightower-api
 spec:
@@ -24,11 +24,11 @@ spec:
               name: http
           env:
             - name: TEMPORAL_ADDRESS
-              value: shannon-temporal:7233
+              value: hightower-temporal:7233
             - name: WORKER_IMAGE
               value: ghcr.io/farhoodliquor/shannon:latest
             - name: K8S_NAMESPACE
-              value: shannon
+              value: hightower
           envFrom:
             - secretRef:
                 name: hightower-credentials