Add Full API Test Coverage

[nensii21]

Description

Several backend endpoints lack automated tests.

Cover
authentication
projects
users
notifications
messages
followers

Acceptance Criteria

Pytest
≥80% coverage for modified modules
CI passes

[Ayush-0918]

Hi @nensii21,

I'd like to work on this issue as part of ECSoC 2026.

My plan is to review the existing backend test suite, identify the uncovered API endpoints, and add Pytest test cases for the authentication, projects, users, notifications, messages, and followers modules. I'll make sure the new tests improve coverage while keeping the existing behavior unchanged and ensuring all CI checks pass.

If this issue is available, I'd be happy to work on it.

Thank you!

[Ayush-0918]

Hi @nensii21,

I started working on this issue and reviewed the current backend structure.

While setting up the test environment, I noticed that the repository currently doesn't include a project-level test suite or existing API tests to extend. I'm reviewing the current structure to determine the best way to introduce Pytest-based API tests while keeping them aligned with the project's architecture and CI requirements.

I'll continue working on this and share a PR once the testing setup is in place.

Thanks!