refactor: rename Planarchy to CapaKraken (branding only)

User-facing rename across 20 files:
- Layout title/meta: "CapaKraken — Resource & Capacity Planning"
- Sidebar logo: "CapaKraken" with "RESOURCE & CAPACITY PLANNING"
- Sign-in page: "CapaKraken Control Center", "Sign in to CapaKraken"
- PWA manifest: name + short_name
- PDF reports: footer text
- Install prompt: "Install CapaKraken"
- AI assistant system prompt
- Webhooks test payload
- Email subject lines
- Tooltips, descriptions, empty states

NOT changed (technical identifiers):
- Package names (@planarchy/*)
- Import paths
- Database names
- Docker container names
- localStorage keys
- Domain URLs
- CLAUDE.md

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/components/admin/WebhooksClient.tsx

@@ -176,7 +176,7 @@ export function WebhooksClient() {
         <div>
           <h1 className="text-2xl font-bold text-gray-900 dark:text-white">Webhooks</h1>
           <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
-            Configure outbound webhooks to notify external services about events in Planarchy.
+            Configure outbound webhooks to notify external services about events in CapaKraken.
           </p>
         </div>
         <button className={PRIMARY_BUTTON} onClick={openCreateModal}>