Updates Cargo.toml, Cargo.lock, and version.txt from 0.3.53 to 0.3.56. Resolves divergent branch changes across configuration files and preserves the macOS .DS_Store binary structure during integration.
Update PMOMusic crate version in Cargo.toml and the project version.txt from 0.3.53 to 0.3.54. Add Serena project configuration by introducing .serena/.gitignore to exclude local cache files, and create .serena/project.yml to set Rust as the language server target with UTF-8 encoding.