feat(readarr): fetch Readarr updates and expose them on the CLI

Adds ReadarrEvent::GetUpdates backed by get_readarr_updates, rendering the
update history into the Readarr updates view, and surfaces it as
'readarr list updates'.

Covers the case where an update record omits the changes key, which the
live instance returns for its most recent release.

src/network/readarr_network/mod.rs

@@ -17,6 +17,7 @@ pub enum ReadarrEvent {
   GetHostConfig,
   GetSecurityConfig,
   GetStatus,
+  GetUpdates,
   HealthCheck,
 }
 
@@ -27,6 +28,7 @@ impl NetworkResource for ReadarrEvent {
       ReadarrEvent::GetDiskSpace => "/diskspace",
       ReadarrEvent::HealthCheck => "/health",
       ReadarrEvent::GetStatus => "/system/status",
+      ReadarrEvent::GetUpdates => "/update",
     }
   }
 }
@@ -56,6 +58,7 @@ impl Network<'_, '_> {
         .await
         .map(ReadarrSerdeable::from),
       ReadarrEvent::GetStatus => self.get_readarr_status().await.map(ReadarrSerdeable::from),
+      ReadarrEvent::GetUpdates => self.get_readarr_updates().await.map(ReadarrSerdeable::from),
       ReadarrEvent::HealthCheck => self
         .get_readarr_healthcheck()
         .await