WP-10: contract and failing tests for OS and package inventory

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

backend/crates/domain/src/ports.rs

@@ -3,6 +3,7 @@ use async_trait::async_trait;
 use uuid::Uuid;
 
 use crate::auth::{AccessClaims, AuthEvent, RefreshToken};
+use crate::host::{Inventory, OsInfo, Package};
 use crate::jobs::{JobKind, JobRun, JobStatus};
 use crate::settings::SmtpSettings;
 use crate::user::{User, UserUpdate};
@@ -76,3 +77,16 @@ pub trait JobRunRepository: Send + Sync {
     async fn find_running(&self, kind: JobKind) -> Result<Option<JobRun>, DomainError>;
     async fn last_finished(&self, kind: JobKind) -> Result<Option<JobRun>, DomainError>;
 }
+
+/// Reads the state of the Debian host.
+#[async_trait]
+pub trait HostInspector: Send + Sync {
+    async fn os_info(&self) -> Result<OsInfo, DomainError>;
+    async fn packages(&self) -> Result<Vec<Package>, DomainError>;
+}
+
+#[async_trait]
+pub trait InventoryRepository: Send + Sync {
+    async fn save(&self, inventory: &Inventory) -> Result<(), DomainError>;
+    async fn load(&self) -> Result<Option<Inventory>, DomainError>;
+}