Add automatic release workflow

[RAprogramm]

Add automatic release workflow to publish new versions to crates.io without manual intervention.

Problem

Currently, releasing a new version requires:

1. Manually updating version in Cargo.toml
2. Manually creating a git tag
3. Manually pushing the tag to trigger release workflow

This is error-prone and slows down the release process.

Solution

Implement automatic release workflow similar to masterror that:

1. Triggers after successful CI on main branch
2. Compares local Cargo.toml version with crates.io version
3. If local version > crates.io version:
   • Checks if tag/release already exists
   • Generates changelog from conventional commits
   • Creates git tag
   • Creates GitHub Release with changelog
   • Triggers existing release.yml workflow

Implementation

Create .github/workflows/auto-release.yml:

• Workflow trigger: after CI completion on main
• Compare versions using semver
• Group commits by type (feat, fix, docs, etc.)
• Generate formatted changelog
• Create annotated git tag
• Create GitHub Release
• Automatic crates.io publish via existing release.yml

Benefits

• Automated release process
• No manual version bumping needed
• Automatic changelog generation
• Faster releases
• Conventional commits enforcement
• Professional release notes

Related

• Similar implementation in masterror: https://github.com/RAprogramm/masterror/.github/workflows/auto-release.yml
• Uses existing release.yml for crates.io publish