## Issue Description

This issue tracks the implementation of role-based access control (RBAC) for the helpyourneighbour project.

## Acceptance Criteria

- [ ] Role middleware is implemented and tested
- [ ] All routes are properly protected by role checks
- [ ] Audit logging is implemented for sensitive actions
- [ ] Documentation is updated with the new RBAC implementation

## Tasks

1. Implement role middleware in `backend/middleware/role.middleware.js`
2. Create tests for role middleware in `backend/tests/roles.test.js`
3. Update existing routes to use role middleware
4. Add audit logging for sensitive actions
5. Update documentation in `docs/roles-and-permissions.md`

## Notes

This issue is a follow-up to the discussion in #42 and aims to implement the role-based access control system as described in the documentation.