Show found desktop updates after manual checks (#1815)

* fix(desktop): report found app updates during manual checks

Manual checks could reuse cached update state while the renderer discarded pending update details. Keep found update versions visible while downloads prepare, and reserve install affordances for ready updates.

* test(desktop): cover manual update retry after errors

* fix(desktop): keep ready updates ready on recheck

packages/desktop/src/features/app-update-service.ts

@@ -163,9 +163,10 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
         });
       },
       onUpdateAvailable(info) {
+        const alreadyReady = downloadedUpdateVersion === info.version;
         cachedUpdateInfo = info;
-        downloadedUpdateVersion = null;
-        downloading = true;
+        downloadedUpdateVersion = alreadyReady ? info.version : null;
+        downloading = !alreadyReady;
         runtimeErrorMessage = null;
       },
       onUpdateDownloaded(info) {
@@ -212,7 +213,12 @@ export function createAppUpdateService(deps: AppUpdateServiceDeps): AppUpdateSer
     }
 
     const cachedVersion = cachedUpdateInfo?.version ?? null;
-    if (!runtimeErrorResult && cachedVersion && cachedVersion !== currentVersion) {
+    if (
+      !runtimeErrorResult &&
+      intent === "automatic" &&
+      cachedVersion &&
+      cachedVersion !== currentVersion
+    ) {
       return buildCheckResult({
         currentVersion,
         hasUpdate: true,