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/api/src/services/job-builder.ts

@@ -21,7 +21,7 @@ export interface JobParams {
   readonly pipelineTesting?: boolean;
 }
 
-const WORKER_LABEL = 'shannon-worker';
+const WORKER_LABEL = 'hightower-worker';
 const REPO_MOUNT_PATH = '/repo';
 
 export function buildJobSpec(params: JobParams): k8s.V1Job {
@@ -36,7 +36,7 @@ export function buildJobSpec(params: JobParams): k8s.V1Job {
 
   // 2. Build volumes and mounts
   const volumes: k8s.V1Volume[] = [
-    { name: 'workspaces', persistentVolumeClaim: { claimName: 'shannon-workspaces' } },
+    { name: 'workspaces', persistentVolumeClaim: { claimName: 'hightower-workspaces' } },
     { name: 'shm', emptyDir: { medium: 'Memory', sizeLimit: '2Gi' } },
   ];