Replace 24 `err: any` error handler types with proper `AxiosError<ApiErrorResponse>`
typing. Fix additional `as any` casts and `Record<string, any>` patterns in registration
field components, event settings, and portal layout. Create shared `ApiErrorResponse`
type for portal app.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Cross-cutting migration affecting the entire stack:
- Database: 3 migrations splitting name columns with data migration
- Models: first_name/last_name on User, Person; contact_first_name/contact_last_name on Company; backward-compatible name accessors
- API: all resources return first_name, last_name, full_name; assignablePersons endpoint updated
- Requests: validation rules updated for all person/user/company forms
- Services: VolunteerRegistrationService, ShiftAssignmentService, InvitationService updated
- Frontend: TypeScript types, Zod schemas, all forms split into Voornaam/Achternaam fields
- Display: all person/user name references use full_name; initials use first_name[0]+last_name[0]
- Tests: all 371 tests passing
- Docs: SCHEMA.md and API.md updated
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
