Sign-out now fully cleans up cached service workers

Old service workers from prior offline-app deploys could intercept the post-sign-out navigation and serve a cached shell that 404'd on JavaScript chunks no longer present on the server. The only workaround was for users to manually clear their site data — a fix path that, frankly, no one figures out on their own.

Sign-out now does three things explicitly:

• Unregisters every service worker the browser knows about.
• Drops every cache from prior deploys.
• Hard-replaces the URL so the browser detaches from any controller still in flight.

The next sign-in lands on a fresh, controller-free page. No more stale 404s, no more cryptic support tickets.