Get Photographers Endpoint

Retrieves photographers for a single project, or the union across multiple projects (the "All Projects" view).

Query Parameters (one of): - projectId: A single project ID - projectIds[]: Multiple project IDs. Photographers are merged by identity (id) across projects, with totalImagesCount summed across them.

Returns: JSON response with list of photographers containing: - id: unique identifier - name: photographer's name - email: photographer's email address - description: additional information about the photographer - isEventOrganizer: boolean indicating if photographer is also an event organizer - totalImagesCount: total number of images uploaded by this photographer

Errors: - 400 if neither projectId nor projectIds[] is provided - 500 if database access fails