v0.12.0

fix: improve GitHub Actions workflows path filters

- Add path filters to rust-test.yml and rust-lint.yml to only run on Rust code changes
- Add path filters to codespell.yml to ignore generated files
- Add nexus-server and nexus-protocol paths to SDK workflows to trigger on API changes
- Add rust-toolchain.toml and .cargo/** to rust-lint.yml paths
- Remove duplicate cli-release.yml workflow (keep release-cli.yml)

This prevents unnecessary workflow runs and ensures SDKs are tested when server API changes.

v0.11.0

fix(tests): use unique labels/types in multiple relationship types te…