Publish Marketplace-backed release refs

[kexi]

Summary

• gate the release workflow on full patch tags and skip floating tag re-triggers
• move both floating major and minor tags, then publish matching release assets
• document the post-initial Marketplace release path and update release contracts

Tests

• nix develop --command cargo fmt --check
• nix develop --command cargo test --test release_asset_name_contract --test marketplace_action_contract
• nix develop --command pinact run -fix=false -verify
• nix develop --command cargo test