fix: category description not shown when no tags available

[Hell1213]

In raising this pull request, I confirm the following (please check boxes):

• I have read and understood the contributors guide.
• I have checked that another pull request for this purpose does not exist.
• I have considered, and confirmed that this submission will be valuable to others.
• I accept that this submission may not be used, and the pull request closed at the will of the maintainer.
• I give this submission freely, and claim no ownership to its content.

My familiarity with the project is as follows (check one):

• I have never used the project.
• I have used the project briefly.
• I have used the project extensively, but have not contributed previously.
• I am an active contributor to the project.

---

Closes #1060

Problem

On /regression/, category descriptions don't show when no tags are available. The description stays hidden even when a category is selected.

Root Cause

JavaScript condition if(hash === "") only checks for empty string, but urlParams.get("category") returns null when no category parameter exists in URL.

Fix

• Changed const hash to let hash for reassignment
• Updated condition to if(!hash || hash === "") to handle both null and empty cases
• Added test case

Files Changed

• templates/regression/index.html: Fixed JavaScript logic
• tests/test_regression/test_controllers.py: Added test

Testing

• All existing tests pass (41 regression tests)
• New test verifies category description HTML structure

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud