Description

Updates the KS2 primary performance page by refreshing the scaled score and GPS explanatory text, correcting scaled score chart axes and label positioning, and fixing top performer ordering when displayed values tie. Adds test coverage for the updated chart and ranking behaviour.

Related Trello Ticket

https://trello.com/c/E1Us7jPo

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Unit tests added/updated
• Integration tests added/updated
• Manual testing performed
• Tested on [Environment: Dev/Staging/Local]

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have verified accessibility requirements are met

Screenshots (if applicable)