Feature/leaderboard pagination 2

[Truphile]

1. Checked out a new branch: feature/leaderboard-pagination-2 (the branch
   name feature/leaderboard-pagination was already in use).
2. Modified app/api/agents/leaderboard/route.ts to fetch all agents from
   agent-health-store .
3. Integrated data retrieval from gamification/xp for the XP fields, and
   reputation/reputation-store for reputation and task count.
4. Implemented dynamic sorting based on the sort query parameter,
   ensuring fallback sorting by agentId to resolve ties.
5. Calculated global rank relative to the full sorted list so ranking
   stays accurate across paginated chunks.
6. Applied limit and offset for pagination along with parameter
   validation (including returning a 400 Bad Request if the limit exceeds

closes #271

[sonarqubecloud]

Quality Gate passed

Issues
20 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