Add issue triage automation, labels, and project board

[danbugs]

Summary

Set up infrastructure for issue management:

1. Auto-triage with labels — add GitHub Actions or bot config to automatically label incoming issues (bug, feature, question, runtime-specific, etc.)
2. Project board — create a GitHub Project board for tracking work across milestones
3. Auto-assign reviewers — configure CODEOWNERS or a review assignment workflow so PRs get routed to the right people

Vision reference

• Repo Assist: A Repository Assistant