fix(server): harden worktree archive with parallel teardown

Fan out agent close + terminal kill concurrently with Promise.allSettled
so one failure never leaves the worktree half-dead. Await real PTY exit
with SIGHUP→SIGKILL escalation before rm to avoid EBUSY races. Tolerate
missing repoRoot and retry directory removal with backoff. Purge stale
client workspace layout/tab state after successful archive.

packages/app/src/stores/checkout-git-actions-store.ts

@@ -1,6 +1,11 @@
 import { create } from "zustand";
 import { useSessionStore } from "@/stores/session-store";
 import { queryClient } from "@/query/query-client";
+import {
+  buildWorkspaceTabPersistenceKey,
+  useWorkspaceLayoutStore,
+} from "@/stores/workspace-layout-store";
+import { useWorkspaceTabsStore } from "@/stores/workspace-tabs-store";
 
 const SUCCESS_DISPLAY_MS = 1000;
 
@@ -123,6 +128,19 @@ function removeWorktreeFromCachedLists(input: { serverId: string; worktreePath:
   );
 }
 
+function purgeArchivedWorkspaceState(input: { serverId: string; worktreePath: string }): void {
+  const serverId = input.serverId.trim();
+  const workspaceId = input.worktreePath.trim();
+  if (!serverId || !workspaceId) {
+    return;
+  }
+  const workspaceKey = buildWorkspaceTabPersistenceKey({ serverId, workspaceId });
+  if (workspaceKey) {
+    useWorkspaceLayoutStore.getState().purgeWorkspace(workspaceKey);
+  }
+  useWorkspaceTabsStore.getState().purgeWorkspace({ serverId, workspaceId });
+}
+
 const successTimers = new Map<string, ReturnType<typeof setTimeout>>();
 const inFlight = new Map<string, Promise<unknown>>();
 
@@ -320,6 +338,7 @@ export const useCheckoutGitActionsStore = create<CheckoutGitActionsStoreState>()
         }
         removeWorktreeFromCachedLists({ serverId, worktreePath });
         invalidateWorktreeList();
+        purgeArchivedWorkspaceState({ serverId, worktreePath });
       },
     });
   },