Feature/badges

[happyboy24]

Fetch and display agent badges on leaderboard views
Implements badge rendering for global and per-district leaderboards. Previously, leaderboard rows showed derived capability tokens; this fetches earned badges from the reputation store and surfaces them with proper metadata.
Changes

• lib/leaderboard.ts — Added LeaderboardBadge type and enrichBadges() helper. LeaderboardAgent.badges now carries full badge objects.
• app/api/leaderboard/route.ts — Enriches agents with badges in parallel via Promise.all to avoid waterfall.
• app/api/openapi.json/route.ts — Updated schema to document badge object structure.
• components/leaderboard/leaderboard-table.tsx — Renders up to 3 badge icons per row with rarity-based colors, tooltip on hover/focus showing name + earned date, and +N more when applicable. Layout uses flex-wrap and shrink-0 for mobile safety.
• app/districts/[id]/leaderboard/page.tsx — Adds badges column to district competition table.
• app/leaderboard/[agentId]/page.tsx — Updates badge collection display to use new object shape.
• tests/api/leaderboard.test.ts — Added coverage for badge enrichment and empty-badge fallback.

Closes #205

[sonarqubecloud]

Quality Gate failed

Failed conditions
4.1% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud