Opt-in Class Leaderboard

[ankit2101]

Summary

An opt-in leaderboard showing the top 10 students by chapter score within the same grade. Admin can toggle it on or off. Students see their own rank even when the full board is hidden.

Why

Leaderboards are the second-strongest achievement motivation driver in Indian school gamification research. The opt-in/admin-toggle design directly addresses known risks of negative social comparison while preserving the motivation benefit.

Implementation Notes

• Add a toggle in Admin Settings: 'Enable class leaderboard'
• New endpoint: GET /api/student/leaderboard?grade=8
• Shows top 10 by average score across all chapters for the grade
• Student always sees their own rank, even if outside top 10
• Names can be shown as first name only for privacy

Acceptance Criteria

• Admin can enable/disable the leaderboard from Settings
• When enabled, students see a leaderboard widget on their home screen
• Leaderboard shows top 10 by average score for the student's grade
• Student's own rank always visible