Harness config 1.0.0-alpha.2

1.0.0-alpha.2 establishes the repository release lane for the alpha package
set.

Release Automation

• Adds GitHub Actions CI for pull requests and protected branch checks.
• Adds tag-driven npm publishing through GitHub Actions OIDC trusted
  publishing.
• Adds release tag verification so all publishable package versions and
  internal package dependency pins must match the pushed vX.Y.Z tag.
• Adds release-note extraction so each GitHub release uses the matching
  version section from this file.

Project Governance

• Documents the dev to main release flow, solo-maintainer review model,
  Codex review evidence pattern, and npm trusted publisher settings.
• Adds pull request, issue, CODEOWNERS, Dependabot, and conduct files for
  open-source project hygiene.