Create Frontend DTO/models #173
Description
The frontend has no shared types for backend entities. Components will fetch API data without typed responses, leading to typos, inconsistent usage, and harder maintenance.
Describe the solution you'd like
Add TypeScript DTOs/models for User, Project, Expenditure, Donor, Donation, and Report in a shared frontend module (e.g. src/types/). Include a Pagination type and a generic PaginatedResponse for list endpoints.
Additional Context
Backend uses snake_case for most responses and camelCase in some places, choose a frontend convention and apply it consistently. Donations map to project_donations.