Release v0.3.0

Fixed

• Ruby 4.0 compatibility: declare ostruct as a dependency (it is required directly but was removed from Ruby's default gems in 4.0.0) and bump activesupport to 7.2.3.1 so its logger dependency is resolved (logger was likewise dropped from default gems).

Removed

• No longer emit the # Variable overrides used: comment in rendered files. Because overrides such as deploySha change on every build, this comment caused large, content-free diffs across every rendered file. --variable-override still applies the overrides to the rendered output; only the comment is removed.