Add GitHub draft release workflow

[Today20092]

What changed

• Add a tag-based release workflow at .github/workflows/release.yml
• Creates a draft release for v* tags
• Generates release notes automatically

Validation

• Not run here (workflow-only change).

Release notes

• Push a tag like �0.1.0 to trigger this workflow and auto-generate notes.
• Add installer artifacts in the GitHub release UI before publishing.