feat: consolidate frontend API layer, add query-client, and harden backend Fase 1

Frontend:
- Consolidate duplicate API layers into single src/lib/axios.ts per app
- Remove src/lib/api-client.ts and src/utils/api.ts (admin)
- Add src/lib/query-client.ts with TanStack Query config per app
- Update all imports and auto-import config

Backend:
- Fix organisations.billing_status default to 'trial'
- Fix user_invitations.invited_by_user_id to nullOnDelete
- Add MeResource with separated app_roles and pivot-based org roles
- Add cross-org check to EventPolicy view() and update()
- Restrict EventPolicy create/update to org_admin/event_manager (not org_member)
- Attach creator as org_admin on organisation store
- Add query scopes to Event and UserInvitation models
- Improve factories with Dutch test data
- Expand test suite from 29 to 41 tests (90 assertions)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -4,7 +4,7 @@
 
 Crewli is a multi-tenant SaaS platform for event and festival management.
 Built for a professional volunteer organisation, with potential to expand as SaaS.
-Design document: `/resources/design/Crewli_Design_Document_v1.3.docx`
+Design document: `/resources/design/design-document.md`
 
 ## Tech stack