chore: update project-stats.yaml (recorded 49, actual 99 merged PRs)

## 📊 Project Stats Are Out of Date

**Recorded `pr_count`:** 49
**Actual merged PRs:** 99
**Difference:** 50 untracked PR(s)

After the next agent session, update `project-stats.yaml`:

```yaml
pr_count: 99
```

Then run `npm run build:project-stats` to regenerate `project-stats-data.js`, or let the deploy workflow handle it.