V2-->OK pour upload 3D dans la scene en -->.glb

fix: 🐛 Resolve database schema mismatch and frontend errors

- Fix conflicting Django migrations and apply merge migration
- Update views.py to work with model_url instead of removed model_file
- Fix undefined $state function and missing imports in frontend
- Remove invalid component props and add proper TypeScript types
- API endpoints now work correctly (GET/POST tested)

Resolves console errors:
- Database column 'model_url' does not exist
- Three.js worldCamProjPosition error
- Zustand deprecated import warnings
- Session fetch errors