Setup unit tests

[naveensingh]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs), in the README and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request may get dismissed otherwise.
• This issue contains only one feature request.

Which apps should have this feature?

All Fossify Apps

Feature description

All Fossify apps should have unit tests, at least for core components such as the calculator implementation.

Why do you want this feature?

Top reasons:

• Helps catch bugs early
• Less manual testing
• Faster feedback in PRs
• It's 2026 🤷

Additional information

Created a dedicated issue to avoid duplicates elsewhere.