Phase 5: Organization Management UI & Components

[leamsigc]

Redesign the UI for team/org management:

• Create /app/organization route (replace /app/business)
• Implement pages: index.vue, [slug]/index.vue (dashboard), members.vue, invites.vue, settings.vue
• Build components: OrgSwitcher, InviteMemberModal, MemberRow, PendingInviteRow, OrgLimitBanner
• Wire up all calls to new organization APIs
• Ensure all API calls use activeOrganization context
• Update/replace useBusinessManager composable with useActiveOrganization
• UX test: create org, invite/join members, org switching, permissions