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/scan-manager.ts

@@ -26,10 +26,10 @@ export async function startScan(
 ): Promise<ScanResponse> {
   const suffix = randomSuffix();
   const taskQueue = `api-${suffix}`;
-  const jobName = `shannon-worker-${suffix}`;
+  const jobName = `hightower-worker-${suffix}`;
 
   const workspace =
-    input.workspace ?? `${new URL(input.targetUrl).hostname.replace(/[^a-zA-Z0-9-]/g, '-')}_shannon-${Date.now()}`;
+    input.workspace ?? `${new URL(input.targetUrl).hostname.replace(/[^a-zA-Z0-9-]/g, '-')}_hightower-${Date.now()}`;
 
   const job = buildJobSpec({
     jobName,