Description
Refactor user module to conform to the unified error model.
What is expected
- Use domain exceptions for validation/not found/conflicts.
- Map Prisma not found/unique errors →
NotFoundException / ConflictException.
What should be modified
src/modules/user/presentation/controllers/*
src/modules/user/* services/use-cases
Tests
- Cover 404 on unknown id, 409 on unique collisions, 400 on invalid DTOs.
Acceptance criteria
- Only domain exceptions used; tests green.