feat: add workspace management editor

frontend/src/shell/AppShell.tsx

@@ -3,6 +3,7 @@ import { useSessionStore } from "../store/sessionStore";
 import { WidgetHost } from "./WidgetHost";
 import { CentralStatus } from "./CentralStatus";
 import { ModelActivityPanel } from "./ModelActivityPanel";
+import { WorkspaceManager } from "./WorkspaceManager";
 import { useActivityPanelResize } from "./useActivityPanelResize";
 import { useSessionPanelResize } from "./useSessionPanelResize";
 import { NavSessions } from "./NavSessions";
@@ -99,6 +100,7 @@ export function AppShell() {
 
   const queryClient = useQueryClient();
   const [showActivity, setShowActivity] = useState(false);
+  const [workspaceManagerOpen, setWorkspaceManagerOpen] = useState(false);
   const [activeOpen, setActiveOpen] = useState(true);
   const [archiveOpen, setArchiveOpen] = useState(false);
   const [renameTarget, setRenameTarget] = useState<SessionSummary | null>(null);
@@ -492,7 +494,7 @@ export function AppShell() {
           </div>
         </div>
       )}
-      {showActivity && <ModelActivityPanel desktopSplit={desktopSplit} onClose={() => setShowActivity(false)} />}
+      {showActivity && <ModelActivityPanel desktopSplit={desktopSplit} onClose={() => setShowActivity(false)} onOpenWorkspaceManager={() => setWorkspaceManagerOpen(true)} />}
       {showActivity && desktopSplit && (
         <div className="relative w-0 shrink-0">
           <div
@@ -608,6 +610,14 @@ export function AppShell() {
           >
             New session
           </Button>
+          <Button
+            variant="outline"
+            size="sm"
+            className="w-full"
+            onClick={() => setWorkspaceManagerOpen(true)}
+          >
+            Workspace management
+          </Button>
         </div>
 
         {principal?.isAdmin && (
@@ -758,6 +768,7 @@ export function AppShell() {
         </div>
         </aside>
       )}
+      <WorkspaceManager open={workspaceManagerOpen} onClose={() => setWorkspaceManagerOpen(false)} />
 
       <Toaster />