Hub stage 2: install, update and uninstall apps on several servers

Writes use only <ID>_ADMIN_TOKEN and need the apps.write capability.
Store URLs are resolved from each server's own listing. The config is saved
to history before an uninstall. Zip uploads are fanned out to the servers.
Every target's result is audited. The console gets a row menu on the
matrix, a target picker, a results dialog with Retry failed, the store and
install from file in All servers mode, and single-server actions for writers.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/app/Shell.tsx

@@ -105,6 +105,8 @@ export interface ShellSession {
     clusterInitialized?: boolean
     /** Only on the hub (`hub/`): a read-only console over several servers. */
     hub?: boolean
+    /** Only on the hub: the servers it holds an admin token for. */
+    hubWritable?: string[]
     /** Only on an initialised cluster (WebServiceAuthApi.cs:104-106). */
     clusterDomain?: string
     clusterNodes?: { name: string; type: string }[]
@@ -649,7 +651,7 @@ export function Shell({
         ) : current?.id === 'about' ? (
           <About info={info} />
         ) : current?.id === 'apps' ? (
-          <Apps token={session.token} nodes={session.info?.clusterNodes ?? []} clusterInitialised={session.info?.clusterInitialized === true} />
+          <Apps token={session.token} nodes={session.info?.clusterNodes ?? []} clusterInitialised={session.info?.clusterInitialized === true} canWrite={permissions?.Apps?.canModify === true} writable={session.info?.hubWritable ?? []} />
         ) : current?.id === 'cache' ? (
           <Cache token={session.token} nodes={session.info?.clusterNodes ?? []} clusterInitialised={session.info?.clusterInitialized === true} />
         ) : current?.id === 'blocking' ? (