Function load_modules 

pub fn load_modules(
    app: &mut App,
    dir: &Path,
    deps: &DependenciesCfg,
    resolved: &ResolvedModules,
    env: &InitEnv,
)

Load every declared dependency into app, in sorted-name order, and record the outcome in a LoadedModules resource. Any failure is a stderr banner plus a failure entry; the app boots without that module.

resolved carries the compiler’s version-source resolutions (see ResolvedModules); pass a default when nothing resolved anything. env is what every portable plugin is told about the app.