Covers #4578/#4579/#4580/#4581 (Python/Go/C++/Rust aliases + Rust union),
#4591 (#4584, C# overload nodes), and #4572 (#4569, package.json dep link).
Each PR shipped a stale 20->21 bump against an older base; this is the single
reconciled bump on top of HEAD's 24.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>