Function install_plugins 

pub fn install_plugins(
    config: &HusakoConfig,
    project_root: &Path,
    progress: &dyn ProgressReporter,
) -> Result<Vec<InstalledPlugin>, HusakoError>

Install all plugins declared in [plugins] to .husako/plugins/<name>/.

For source = "git", shallow-clones the repository. For source = "path", copies the directory contents.

Returns a list of installed plugins with their parsed manifests.