crates.io publish

[ajianaz]

crates.io Publishing

Prepare and publish cora to crates.io.

Checklist

• Verify all metadata in Cargo.toml is correct
• Ensure no sensitive data or large files in crate
• Test cargo publish --dry-run passes
• Set up CARGO_REGISTRY_TOKEN in GitHub secrets
• Verify release workflow publishes on tag push
• Verify crate page has good description, keywords, categories
• Post-publish: update README badges with actual crate link

[ajianaz]

Post-launch priority — tracked for future release