fix(apps): stop reinstall from yanking the user out of the agent dialog

Two races around the post-install prompt:

- AppsView kept a stale selectedFolder after the open app was
  uninstalled; on reinstall the 4s apps:list poll matched it again and
  instantly swapped in the app frame, unmounting the catalog and the
  enable-agents dialog mid-choice. Clear the selection when its app
  disappears from the list.

- Bundled agents materialized on the NEXT apps:list poll, not at
  install — so the dialog's bg-task:get/patch hit a task that didn't
  exist yet if the user acted within ~4s. Install handlers now call
  syncAppAgents synchronously.

apps/x/apps/main/src/ipc.ts

@@ -1646,6 +1646,9 @@ export function setupIpcHandlers() {
       const preview = appInstallPreviews.get(args.name) ?? await appsInstaller.previewInstall(record);
       const result = await appsInstaller.installFromRegistry(record, preview);
       appInstallPreviews.delete(args.name);
+      // Materialize bundled agents NOW, not on the next apps:list poll — the
+      // renderer's post-install enable dialog patches these tasks immediately.
+      if (result.app) await appsAgents.syncAppAgents(result.app);
       capture('app_installed', { name: args.name });
       return result;
     },
@@ -1654,6 +1657,7 @@ export function setupIpcHandlers() {
         return appsInstaller.previewUrlInstall(args.url);
       }
       const result = await appsInstaller.confirmUrlInstall(args.url);
+      if (result.app) await appsAgents.syncAppAgents(result.app);
       capture('app_installed', { name: result.app.manifest?.name ?? result.app.folder });
       return result;
     },

apps/x/apps/renderer/src/components/apps/apps-view.tsx

@@ -186,6 +186,11 @@ export function AppsView({ initialAppFolder, initialVersion, onNewApp }: {
         const r = await window.ipc.invoke('apps:list', {})
         if (cancelled) return
         setApps(r.apps)
+        // Drop a selection whose app no longer exists (uninstalled while
+        // open). Left stale, a later reinstall makes this view yank the user
+        // into the app frame mid-flow — e.g. while they're in the catalog's
+        // post-install agent dialog.
+        setSelectedFolder((cur) => (cur && !r.apps.some((a) => a.folder === cur) ? null : cur))
         setServerError(r.serverRunning ? null : (r.serverError ?? 'Apps server is not running.'))
       } catch (e) {
         if (!cancelled) setServerError(e instanceof Error ? e.message : String(e))