Fix/num traits peer dependency

[piliugin-anton]

fix: include num-traits in Cargo.toml when num-derive is used

Problem

When syncCargoToml: true, the generated Cargo.toml includes num-derive but not num-traits, causing error[E0463]: can't find crate for num_traits. Although num-traits is listed in DEFAULT_DEPENDENCY_VERSIONS, that map is only a version lookup table — a dependency only gets added to Cargo.toml if it's first detected as "used" by scanning rendered source for crate references. The scanner correctly finds num_derive from #[derive(num_derive::FromPrimitive)] in generated code, but num_traits never appears in source — it's only referenced inside the proc-macro expansion that rustc produces at compile time. Since the scanner never sees num_traits, it's never looked up in DEFAULT_DEPENDENCY_VERSIONS and never written to Cargo.toml.

Fix

Adds a PEER_DEPENDENCIES map that declares runtime crates required by proc-macro crates (num-derive → num-traits). After the initial import scan in getUsedDependencyVersions(), a new expandPeerDependencies() step adds any missing peers, respecting user-provided version overrides and routing unresolvable peers through the existing error path.

[changeset-bot]

🦋 Changeset detected

Latest commit: 676d1e5

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@codama/renderers-rust	Patch

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