/claim #71

Summary

• Added focused Vitest coverage for StatsPlugin registration.
• Covered middleware capture of config/dataSource.
• Covered admin stats response merging rpc.getStatistics() with registry.currentPlugins().
• Covered non-admin rejection before statistics are read.

This is a test-only PR with no production behavior changes.

Verification

• pnpm vitest --run plugins/stats/index.test.ts -> 3 tests passed
• pnpm exec prettier --check plugins/stats/index.test.ts -> passed
• git diff --check -> passed
• pnpm vitest --run -> existing baseline still has 4 failing RLS tests in src/rls/index.test.ts; the new stats test passes in the full run

AI-assisted with Codex; I reviewed the diff and kept the scope to the Stats plugin coverage slice.