Fix Clerk profile routing and support users without organizations

Clerk profile UI no longer breaks routing or crashes for users without an organization — Profile components now use hash-based routing so Clerk's internal navigation won't conflict with Next.js paths. The organization settings page now shows a "Create organization" prompt for users who don't have an active org, and users are no longer forced through an onboarding redirect.

Added routing="hash" to Clerk's OrganizationProfile and UserProfile components to avoid path-based navigation conflicts with Next.js.frontend
Updated the organization settings page to guard against missing organizations: it now renders a CreateOrganization prompt instead of failing when no org is active.frontend
Removed the mandatory redirect to /app/onboarding when an organization ID was absent; projects are now scoped to the user when no org is active.frontend

Updated the changelog to describe the routing fix and the org-less user behavior change.frontend