WP-20/21: contract and failing tests for vulnerability management

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

backend/crates/application/src/lib.rs

@@ -7,6 +7,7 @@ pub mod scheduler;
 pub mod settings_service;
 pub mod upgrade_service;
 pub mod user_service;
+pub mod vuln_service;
 
 pub use auth_service::AuthService;
 pub use cluster_service::ClusterService;
@@ -15,6 +16,7 @@ pub use jobs::{JobHandler, JobLog, JobRunner};
 pub use settings_service::SettingsService;
 pub use upgrade_service::{PackageUpgradeJob, UpgradeParams};
 pub use user_service::UserService;
+pub use vuln_service::{VulnerabilityScanJob, VulnerabilityService};
 
 #[cfg(test)]
 pub(crate) mod test_fakes;