WP-10: OS and package inventory

Debian inspector (dpkg-query, apt-get -s upgrade, snap list, os-release,
reboot-required) behind a CommandRunner port with tested parsers, fake
inspector for dev, persisted inventory snapshot, package_refresh job,
/api/system/inventory, Updates page with OS card, summary and filterable
package table.

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

backend/crates/application/src/inventory_service.rs

@@ -1,6 +1,7 @@
 use std::sync::Arc;
 
 use async_trait::async_trait;
+use chrono::Utc;
 use domain::host::Inventory;
 use domain::ports::{HostInspector, InventoryRepository};
 use domain::DomainError;
@@ -14,18 +15,26 @@ pub struct InventoryService {
 
 impl InventoryService {
     pub fn new(inspector: Arc<dyn HostInspector>, repo: Arc<dyn InventoryRepository>) -> Self {
-        let _ = (&inspector, &repo);
         Self { inspector, repo }
     }
 
     /// Query the host and persist a new snapshot.
     pub async fn refresh(&self) -> Result<Inventory, DomainError> {
-        todo!()
+        let os = self.inspector.os_info().await?;
+        let mut packages = self.inspector.packages().await?;
+        packages.sort_by(|a, b| a.name.cmp(&b.name));
+        let inventory = Inventory {
+            os,
+            packages,
+            refreshed_at: Utc::now(),
+        };
+        self.repo.save(&inventory).await?;
+        Ok(inventory)
     }
 
     /// Last persisted snapshot.
     pub async fn current(&self) -> Result<Option<Inventory>, DomainError> {
-        todo!()
+        self.repo.load().await
     }
 }
 
@@ -34,7 +43,27 @@ pub struct PackageRefreshJob(pub Arc<InventoryService>);
 
 #[async_trait]
 impl JobHandler for PackageRefreshJob {
-    async fn run(&self, _params: Option<String>, _log: &dyn JobLog) -> Result<(), String> {
-        todo!()
+    async fn run(&self, _params: Option<String>, log: &dyn JobLog) -> Result<(), String> {
+        log.line("querying host for OS and package information")
+            .await;
+        let inv = self.0.refresh().await.map_err(|e| e.to_string())?;
+        log.line(&format!(
+            "{} {} on kernel {}",
+            inv.os.name, inv.os.version, inv.os.kernel
+        ))
+        .await;
+        log.line(&format!(
+            "{} packages, {} upgradable ({} security){}",
+            inv.packages.len(),
+            inv.upgradable(),
+            inv.security_upgrades(),
+            if inv.os.reboot_required {
+                ", reboot required"
+            } else {
+                ""
+            }
+        ))
+        .await;
+        Ok(())
     }
 }