fix(social): exclude inactive accounts from follow rankings

[aiirvizionz]

Fixes #125.

The profile counter already excludes suspended/deleted accounts, but both follow leaderboards only filter the ranked user. A suspended or deleted account can therefore inflate the public follower/following totals.

Changes:

• join the other side of each follow edge and require both users to be active
• add in-memory regression coverage for active, suspended, and deleted users

Tests:

• pnpm --filter @aiornot/web exec vitest run lib/social.test.ts
• 2 tests passed