Function is_plugin_enabled_at_project_scope 

pub fn is_plugin_enabled_at_project_scope(plugin_id: &str) -> bool

Is this plugin enabled (value === true) in .claude/settings.json?

Distinct from V2 installed_plugins.json scope: that file tracks where a plugin was installed from, but the same plugin can also be enabled at project scope via settings. The uninstall UI needs to check THIS, because a user-scope install with a project-scope enablement means “uninstall” would succeed at removing the user install while leaving the project enablement active – the plugin keeps running.