Add tests for the images API

[PranjaliBhardwaj]

There are backend tests for albums, face clusters, folders, and user preferences, but none for the images routes in backend/app/routes/images.py.
work: Add backend/tests/test_images.py that:
Uses the same style as test_albums.py.
Covers at least:
GET / (and optionally the tagged query).
POST /toggle-favourite (success and “image not found” or error path).
This improves coverage and protects the images API from regressions.

[github-actions]

👋 Thanks for opening this issue! The maintainers will review it shortly. Till then, do not open any PR. This is a strict rule we like to follow around here :)

[ionfwsrijan]

@PranjaliBhardwaj
Hi there,

I’m Srijan Jaiswal, and I’m eager to contribute to this project as part of my open-source contribution. I have reviewed this issue and feel confident that I can provide a solution since I have experience working with similar technologies in my past projects. Could you please assign this issue to me? I’d love to work on it and contribute to the project.

Best regards,
Srijan Jaiswal