WP-11: contract and failing tests for package upgrades

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

backend/crates/application/src/upgrade_service.rs

@@ -0,0 +1,48 @@
+//! Package upgrade job: runs the host updater, streams its output into the job log,
+//! then refreshes the inventory.
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use domain::host::validate_package_name;
+use domain::ports::HostUpdater;
+use domain::DomainError;
+use serde::{Deserialize, Serialize};
+
+use crate::jobs::{JobHandler, JobLog};
+use crate::InventoryService;
+
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct UpgradeParams {
+    /// Empty = upgrade all packages.
+    #[serde(default)]
+    pub packages: Vec<String>,
+}
+
+impl UpgradeParams {
+    pub fn validate(&self) -> Result<(), DomainError> {
+        self.packages
+            .iter()
+            .try_for_each(|p| validate_package_name(p))
+    }
+
+    pub fn to_json(&self) -> String {
+        serde_json::to_string(self).unwrap_or_default()
+    }
+
+    pub fn from_json(s: Option<&str>) -> Result<Self, DomainError> {
+        let _ = s;
+        todo!()
+    }
+}
+
+pub struct PackageUpgradeJob {
+    pub updater: Arc<dyn HostUpdater>,
+    pub inventory: Arc<InventoryService>,
+}
+
+#[async_trait]
+impl JobHandler for PackageUpgradeJob {
+    async fn run(&self, _params: Option<String>, _log: &dyn JobLog) -> Result<(), String> {
+        todo!()
+    }
+}