fix: resolve mobile Add folder executor race in workspace sources (#2696)

Co-authored-by: ayattara <alassane.yattara@savoirfairelinux.com> Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com> Co-authored-by: Carlos Florencio <carlosmflorencio@gmail.com>
2026-08-22 16:30:45 +00:00
parent 34f7f56714
commit faed669371
18 changed files with 430 additions and 51 deletions
@@ -0,0 +1,38 @@
+import { IconFolderPlus } from "@tabler/icons-react";
+import { Button } from "@kandev/ui/button";
+import { useTranslation } from "react-i18next";
+import { cn } from "@/lib/utils";
+import { getWorkspaceSourceCapabilities } from "@/components/workspace-source-picker/executor-capabilities";
+import { type WorkspaceSourceRow } from "@/components/workspace-source-picker/workspace-source-state";
+
+export function AddFolderButton({
+  isMobile,
+  capabilities,
+  onAdd,
+}: {
+  isMobile: boolean;
+  capabilities: ReturnType<typeof getWorkspaceSourceCapabilities>;
+  onAdd: (kind: NonNullable<WorkspaceSourceRow["sourceType"]>) => void;
+}) {
+  const { t } = useTranslation();
+  if (!capabilities.canAddFolders && capabilities.executorCapabilitiesKnown) return null;
+  return (
+    <Button
+      type="button"
+      variant="outline"
+      disabled={!capabilities.canAddFolders}
+      className={cn("cursor-pointer", isMobile ? "min-h-11" : "h-9 px-3")}
+      onClick={() => onAdd("folder")}
+    >
+      <IconFolderPlus className="h-4 w-4" />
+      <span className="flex flex-col items-start">
+        <span>{t("task:addFolder")}</span>
+        {!capabilities.executorCapabilitiesKnown && (
+          <span className="text-xs text-muted-foreground normal-case">
+            {t("task:addFolderExecutorUnknown")}
+          </span>
+        )}
+      </span>
+    </Button>
+  );
+}
@@ -49,13 +49,9 @@ function openRepositoryMenu() {
  return trigger;
 }

-function Harness({
-  makeTurnActive = false,
-  executorType = "worktree",
-}: {
-  makeTurnActive?: boolean;
-  executorType?: string;
-}) {
+function Harness(props: { makeTurnActive?: boolean; executorType?: string | null }) {
+  const makeTurnActive = props.makeTurnActive ?? false;
+  const executorType = Object.hasOwn(props, "executorType") ? props.executorType : "worktree";
  return (
    <StateProvider>
      <HarnessContent makeTurnActive={makeTurnActive} executorType={executorType} />
@@ -68,7 +64,7 @@ function HarnessContent({
  executorType,
 }: {
  makeTurnActive: boolean;
-  executorType: string;
+  executorType: string | null | undefined;
 }) {
  const [open, setOpen] = useState(false);
  const [opener, setOpener] = useState<HTMLElement | null>(null);
@@ -199,6 +195,26 @@ describe("AddWorkspaceSourcesDialog", () => {
    expect(form.querySelectorAll('[role="alert"]')).toHaveLength(2);
  });

+  it.each([null, undefined])(
+    "shows Add folder disabled with a touch-visible reason while the executor is unresolved (%s)",
+    async (executorType) => {
+      render(<Harness executorType={executorType} />);
+
+      fireEvent.click(screen.getByRole("button", { name: ADD_SOURCES_LABEL }));
+      const addFolder = screen.getByRole("button", { name: /Add folder/ }) as HTMLButtonElement;
+      expect(addFolder.disabled).toBe(true);
+      const hint = screen.getByText("Waiting to confirm this task's executor supports folders");
+      expect(hint.className).toContain("text-xs");
+    },
+  );
+
+  it("keeps Add folder absent once the executor is known not to support folders", async () => {
+    render(<Harness executorType="local_docker" />);
+
+    fireEvent.click(screen.getByRole("button", { name: ADD_SOURCES_LABEL }));
+    expect(screen.queryByRole("button", { name: /Add folder/ })).toBeNull();
+  });
+
  it.each([
    ["desktop", false, "add-workspace-sources-dialog"],
    ["mobile", true, "add-workspace-sources-drawer"],
@@ -4,7 +4,6 @@ import { useCallback, useEffect, useState, type RefObject, type ReactNode } from
 import {
  IconChevronDown,
  IconCloudDownload,
-  IconFolderPlus,
  IconGitBranch,
  IconPlus,
  IconStack2,
@@ -47,6 +46,7 @@ import {
  getWorkspaceSourceCapabilities,
  hasCloneableSavedRepository,
 } from "@/components/workspace-source-picker/executor-capabilities";
+import { AddFolderButton } from "./add-folder-button";
 import { SavedRepositorySourceRow } from "./saved-repository-source-row";
 import { useDialogOpenerFocus } from "./use-dialog-opener-focus";
 import { useSubmitWorkspaceSources } from "./use-submit-workspace-sources";
@@ -318,17 +318,7 @@ function SourceForm({
    <div className="space-y-4 py-1" data-testid="add-workspace-sources-form">
      <div className="flex flex-wrap items-center gap-2">
        <RepositorySourceMenu isMobile={isMobile} onAdd={onAdd} />
-        {capabilities.canAddFolders && (
-          <Button
-            type="button"
-            variant="outline"
-            className={cn("cursor-pointer", isMobile ? "min-h-11" : "h-9 px-3")}
-            onClick={() => onAdd("folder")}
-          >
-            <IconFolderPlus className="h-4 w-4" />
-            {t("task:addFolder")}
-          </Button>
-        )}
+        <AddFolderButton isMobile={isMobile} capabilities={capabilities} onAdd={onAdd} />
      </div>
      {capabilities.requiresCloneableLocalRepository && (
        <p className="text-sm text-muted-foreground">
@@ -17,6 +17,37 @@ describe("getWorkspaceSourceCapabilities", () => {
    },
  );

+  it.each([
+    "local",
+    "local_pc",
+    "worktree",
+    "local_docker",
+    "remote_docker",
+    "ssh",
+    "sprites",
+    "remote_vps",
+    "k8s",
+  ] as const)("marks executor capabilities as known once resolved for %s", (executorType) => {
+    expect(getWorkspaceSourceCapabilities(executorType).executorCapabilitiesKnown).toBe(true);
+  });
+
+  it.each([null, undefined])(
+    "marks executor capabilities as unknown, not unsupported, for %s",
+    (executorType) => {
+      expect(getWorkspaceSourceCapabilities(executorType)).toMatchObject({
+        canAddFolders: false,
+        executorCapabilitiesKnown: false,
+      });
+    },
+  );
+
+  it("keeps an unrecognized executor type unresolved", () => {
+    expect(getWorkspaceSourceCapabilities("future_executor")).toMatchObject({
+      canAddFolders: false,
+      executorCapabilitiesKnown: false,
+    });
+  });
+
  it.each(["local", "local_pc"] as const)(
    "uses the live checkout and does not offer a checkout branch for %s",
    (executorType) => {
@@ -1,5 +1,17 @@
 import type { ExecutorType } from "@/lib/types/http";

+const KNOWN_EXECUTOR_TYPES = new Set<ExecutorType>([
+  "local",
+  "local_pc",
+  "local_docker",
+  "sprites",
+  "ssh",
+  "remote_docker",
+  "remote_vps",
+  "k8s",
+  "worktree",
+]);
+
 type SavedRepositoryIdentity = {
  remote_url?: string;
  provider?: string;
@@ -15,6 +27,12 @@ export function getWorkspaceSourceCapabilities(
  canAddFolders: boolean;
  canChooseCheckoutBranch: boolean;
  requiresCloneableLocalRepository: boolean;
+  /**
+   * False while the primary executor binding has not resolved yet or the type
+   * is unknown. Callers must not treat that the same as a known executor that
+   * cannot host folders — an unresolved capability means "not yet known," not "no."
+   */
+  executorCapabilitiesKnown: boolean;
 } {
  const usesLiveCheckout = executorType === "local" || executorType === "local_pc";
  const requiresClone =
@@ -26,6 +44,7 @@ export function getWorkspaceSourceCapabilities(
    canAddFolders: usesLiveCheckout || executorType === "worktree",
    canChooseCheckoutBranch: !usesLiveCheckout,
    requiresCloneableLocalRepository: requiresClone,
+    executorCapabilitiesKnown: KNOWN_EXECUTOR_TYPES.has(executorType as ExecutorType),
  };
 }

@@ -2202,6 +2202,7 @@ export class ApiClient {
    title: string;
    autopilot?: boolean;
    primary_session_id?: string | null;
+    primary_executor_type?: string | null;
    state?: string;
    workflow_step_id?: string;
    parent_id?: string;
@@ -104,6 +104,19 @@ test.describe("Attach local workspace sources", () => {

    if (!task.session_id) throw new Error("task creation did not return a session id");
    await waitForWorkspaceReady(apiClient, task.id, task.session_id);
+
+    // The "Add folder" control is gated on the task's primary executor
+    // binding. Poll the backend directly for it rather than relying on the
+    // later "Add folder" click landing after it incidentally.
+    // `primary_executor_type` is `omitempty`, so an unbound task omits the key
+    // entirely: assert truthiness, never `not.toBeNull()`, which `undefined`
+    // satisfies on the first poll.
+    await expect
+      .poll(async () => (await apiClient.getTask(task.id)).primary_executor_type, {
+        timeout: 30_000,
+      })
+      .toBeTruthy();
+
    await testPage.goto(`/t/${task.id}`);
    const session = new SessionPage(testPage);
    await session.waitForLoad();
@@ -56,6 +56,19 @@ test("mobile Files drawer attaches sources with fixed controls and persisted wor
    },
  );

+  // The "Add folder" control is gated on the task's primary executor binding.
+  // Poll the backend directly for it rather than budgeting the later UI
+  // assertion for the async session launch that produces it. The budget sits on
+  // the backend cause, not on a UI shadow of it, so the "Add folder" assertion
+  // below keeps the default timeout. `primary_executor_type` is `omitempty`, so
+  // an unbound task omits the key entirely: assert truthiness, never
+  // `not.toBeNull()`, which `undefined` satisfies on the first poll.
+  await expect
+    .poll(async () => (await apiClient.getTask(task.id)).primary_executor_type, {
+      timeout: 30_000,
+    })
+    .toBeTruthy();
+
  await testPage.goto(`/t/${task.id}`);
  const session = new SessionPage(testPage);
  await session.waitForLoad();
@@ -147,14 +160,11 @@ test("mobile Files drawer attaches sources with fixed controls and persisted wor
  const addRepository = drawer.getByRole("button", { name: "Add repository" });
  const addFolder = drawer.getByRole("button", { name: "Add folder" });
  const submit = drawer.getByTestId("add-workspace-sources-submit");
-  // The "Add folder" control is gated on activeTask.primaryExecutorType, which
-  // arrives from a follow-up office.task.updated WS event once the primary
-  // session's executor is bound and can lag the drawer mount on a loaded CI
-  // shard. The drawer re-renders reactively when that field hydrates, so wait
-  // for the button with a generous timeout instead of measuring a not-yet-
-  // rendered button (a null box that otherwise stalls until the suite timeout).
+  // The "Add folder" control is gated on activeTask.primaryExecutorType. The
+  // poll before navigation already confirmed the backend has resolved it, so
+  // the drawer renders it on first paint and this needs no extended budget.
  await expect(addRepository).toBeVisible();
-  await expect(addFolder).toBeVisible({ timeout: 30_000 });
+  await expect(addFolder).toBeVisible();
  const [addRepositoryBox, addFolderBox] = await Promise.all([
    addRepository.boundingBox(),
    addFolder.boundingBox(),
@@ -222,6 +222,25 @@ describe("useAllWorkflowSnapshots — fetch guards", () => {
  });
 });

+const WORKTREE_EXECUTOR_FIELDS = {
+  primaryExecutorId: "exec-worktree",
+  primaryExecutorType: "worktree",
+  primaryExecutorName: "Worktree",
+  isRemoteExecutor: false,
+};
+
+function seedCachedTask(taskOverrides: Record<string, unknown>) {
+  mockState.kanbanMulti.snapshots = {
+    "wf-A": {
+      workflowId: "wf-A",
+      workflowName: "A",
+      isPlaceholder: true,
+      steps: [],
+      tasks: [{ id: "task-1", workflowStepId: "step-1", ...taskOverrides }],
+    },
+  };
+}
+
 describe("useAllWorkflowSnapshots — snapshot mapping", () => {
  beforeEach(() => {
    resetMocks([{ id: "wf-A", workspaceId: "ws-A", name: "A" }]);
@@ -255,15 +274,7 @@ describe("useAllWorkflowSnapshots — snapshot mapping", () => {
  });

  it("preserves a cached autopilot marker when a fresh snapshot omits it", async () => {
-    mockState.kanbanMulti.snapshots = {
-      "wf-A": {
-        workflowId: "wf-A",
-        workflowName: "A",
-        isPlaceholder: true,
-        steps: [],
-        tasks: [{ id: "task-1", workflowStepId: "step-1", autopilot: true }],
-      },
-    };
+    seedCachedTask({ autopilot: true });
    mockFetchWorkflowSnapshot.mockResolvedValueOnce({
      steps: [{ id: "step-1", name: "Review", position: 1 }],
      tasks: [{ id: "task-1", workflow_step_id: "step-1", title: "Task" }],
@@ -276,15 +287,7 @@ describe("useAllWorkflowSnapshots — snapshot mapping", () => {
  });

  it("keeps an explicit false autopilot value from the fresh snapshot", async () => {
-    mockState.kanbanMulti.snapshots = {
-      "wf-A": {
-        workflowId: "wf-A",
-        workflowName: "A",
-        isPlaceholder: true,
-        steps: [],
-        tasks: [{ id: "task-1", workflowStepId: "step-1", autopilot: true }],
-      },
-    };
+    seedCachedTask({ autopilot: true });
    mockFetchWorkflowSnapshot.mockResolvedValueOnce({
      steps: [{ id: "step-1", name: "Review", position: 1 }],
      tasks: [{ id: "task-1", workflow_step_id: "step-1", title: "Task", autopilot: false }],
@@ -297,6 +300,152 @@ describe("useAllWorkflowSnapshots — snapshot mapping", () => {
  });
 });

+describe("useAllWorkflowSnapshots — executor binding merge", () => {
+  beforeEach(() => {
+    resetMocks([{ id: "wf-A", workspaceId: "ws-A", name: "A" }]);
+  });
+
+  it("preserves a newer live executor binding when a delayed snapshot omits it", async () => {
+    seedCachedTask({});
+    let resolveSnapshot: (value: { steps: unknown[]; tasks: unknown[] }) => void = () => {};
+    mockFetchWorkflowSnapshot.mockImplementationOnce(
+      () =>
+        new Promise((resolve) => {
+          resolveSnapshot = resolve;
+        }),
+    );
+
+    renderHook(() => useAllWorkflowSnapshots("ws-A"));
+    await waitFor(() => expect(mockFetchWorkflowSnapshot).toHaveBeenCalled());
+
+    // A task.updated event adds the executor while the snapshot is in flight.
+    mockState.kanbanMulti.snapshots = {
+      "wf-A": {
+        workflowId: "wf-A",
+        workflowName: "A",
+        isPlaceholder: true,
+        steps: [],
+        tasks: [{ id: "task-1", workflowStepId: "step-1", ...WORKTREE_EXECUTOR_FIELDS }],
+      },
+    };
+    resolveSnapshot({
+      steps: [{ id: "step-1", name: "Review", position: 1 }],
+      tasks: [{ id: "task-1", workflow_step_id: "step-1", title: "Task" }],
+    });
+
+    await waitFor(() => expect(mockSetWorkflowSnapshot).toHaveBeenCalled());
+    expect(mockSetWorkflowSnapshot.mock.calls[0][1].tasks[0]).toMatchObject(
+      WORKTREE_EXECUTOR_FIELDS,
+    );
+  });
+
+  it("clears a cached executor when a current snapshot omits the primary session", async () => {
+    seedCachedTask({ primarySessionId: "session-1", ...WORKTREE_EXECUTOR_FIELDS });
+    mockFetchWorkflowSnapshot.mockResolvedValueOnce({
+      steps: [{ id: "step-1", name: "Review", position: 1 }],
+      // The backend omits primary_session_id and primary_executor_* when the
+      // task has no primary session because those DTO fields use omitempty.
+      tasks: [{ id: "task-1", workflow_step_id: "step-1", title: "Task" }],
+    });
+
+    renderHook(() => useAllWorkflowSnapshots("ws-A"));
+
+    await waitFor(() => expect(mockSetWorkflowSnapshot).toHaveBeenCalled());
+    expect(mockSetWorkflowSnapshot.mock.calls[0][1].tasks[0].primaryExecutorType).toBeUndefined();
+  });
+
+  it("preserves each omitted executor field from a newer live binding independently", async () => {
+    seedCachedTask({});
+    let resolveSnapshot: (value: { steps: unknown[]; tasks: unknown[] }) => void = () => {};
+    mockFetchWorkflowSnapshot.mockImplementationOnce(
+      () =>
+        new Promise((resolve) => {
+          resolveSnapshot = resolve;
+        }),
+    );
+
+    renderHook(() => useAllWorkflowSnapshots("ws-A"));
+    await waitFor(() => expect(mockFetchWorkflowSnapshot).toHaveBeenCalled());
+
+    mockState.kanbanMulti.snapshots = {
+      "wf-A": {
+        workflowId: "wf-A",
+        workflowName: "A",
+        isPlaceholder: true,
+        steps: [],
+        tasks: [{ id: "task-1", workflowStepId: "step-1", ...WORKTREE_EXECUTOR_FIELDS }],
+      },
+    };
+    resolveSnapshot({
+      steps: [{ id: "step-1", name: "Review", position: 1 }],
+      tasks: [
+        {
+          id: "task-1",
+          workflow_step_id: "step-1",
+          title: "Task",
+          primary_executor_type: "worktree",
+        },
+      ],
+    });
+
+    await waitFor(() => expect(mockSetWorkflowSnapshot).toHaveBeenCalled());
+    expect(mockSetWorkflowSnapshot.mock.calls[0][1].tasks[0]).toMatchObject(
+      WORKTREE_EXECUTOR_FIELDS,
+    );
+  });
+});
+
+describe("useAllWorkflowSnapshots — executor binding mapping", () => {
+  beforeEach(() => {
+    resetMocks([{ id: "wf-A", workspaceId: "ws-A", name: "A" }]);
+  });
+
+  it("clears a cached executor binding when the response explicitly clears the primary session", async () => {
+    seedCachedTask({ primarySessionId: "session-1", ...WORKTREE_EXECUTOR_FIELDS });
+    mockFetchWorkflowSnapshot.mockResolvedValueOnce({
+      steps: [{ id: "step-1", name: "Review", position: 1 }],
+      tasks: [
+        {
+          id: "task-1",
+          workflow_step_id: "step-1",
+          title: "Task",
+          primary_session_id: null,
+        },
+      ],
+    });
+
+    renderHook(() => useAllWorkflowSnapshots("ws-A"));
+
+    await waitFor(() => expect(mockSetWorkflowSnapshot).toHaveBeenCalled());
+    expect(mockSetWorkflowSnapshot.mock.calls[0][1].tasks[0].primaryExecutorType).toBeUndefined();
+  });
+
+  it("adopts a fresh primary executor binding when the response includes one", async () => {
+    seedCachedTask({});
+    mockFetchWorkflowSnapshot.mockResolvedValueOnce({
+      steps: [{ id: "step-1", name: "Review", position: 1 }],
+      tasks: [
+        {
+          id: "task-1",
+          workflow_step_id: "step-1",
+          title: "Task",
+          primary_executor_id: "exec-worktree",
+          primary_executor_type: "worktree",
+          primary_executor_name: "Worktree",
+          is_remote_executor: false,
+        },
+      ],
+    });
+
+    renderHook(() => useAllWorkflowSnapshots("ws-A"));
+
+    await waitFor(() => expect(mockSetWorkflowSnapshot).toHaveBeenCalled());
+    expect(mockSetWorkflowSnapshot.mock.calls[0][1].tasks[0]).toMatchObject(
+      WORKTREE_EXECUTOR_FIELDS,
+    );
+  });
+});
+
 const REMOTE_EXECUTOR_NAME = "Remote box";

 function seedExecutor(executor: Record<string, unknown>) {
@@ -55,10 +55,23 @@ function hasNewerLiveExecutor(existing: KanbanTask, fetchStart: KanbanTask | und
  );
 }

+function preserveLiveExecutorBinding(
+  merged: KanbanTask,
+  existing: KanbanTask,
+  fetchStart: KanbanTask | undefined,
+  source: Task,
+): void {
+  // An explicit primary-session clear is authoritative, even if a newer live
+  // update changed the cached executor while this snapshot was in flight.
+  if (source.primary_session_id === null || !hasNewerLiveExecutor(existing, fetchStart)) return;
+  copyPrimaryExecutorFields(merged, existing);
+}
+
 function mergeFetchedTask(
  mapped: KanbanTask,
  existing: KanbanTask,
  fetchStart: KanbanTask | undefined,
+  source: Task,
  statusSummaryInvalidated: boolean,
 ): KanbanTask {
  // Production snapshot payloads can be surfaced through read-only objects.
@@ -100,12 +113,7 @@ function mergeFetchedTask(
  if (merged.autoStartFailed === undefined || hasNewerLiveAutoStartFailed(existing, fetchStart)) {
    merged.autoStartFailed = existing.autoStartFailed;
  }
-  // An omitted executor bundle in a current full snapshot represents a
-  // legitimate detach. Only copy live fields when a live update changed the
-  // executor after this request began, or when the task appeared in flight.
-  if (hasNewerLiveExecutor(existing, fetchStart)) {
-    copyPrimaryExecutorFields(merged, existing);
-  }
+  preserveLiveExecutorBinding(merged, existing, fetchStart, source);
  return merged;
 }

@@ -132,6 +140,7 @@ function mergeSnapshotTasks(
            mapped,
            existing,
            fetchStartById.get(mapped.id),
+            task,
            task.status_summary_invalidated === true,
          )
        : mapped;
@@ -1,6 +1,11 @@
 import { describe, expect, it } from "vitest";
+import { produce } from "immer";
+import type { Draft } from "immer";

 import { snapshotToState } from "./mapper";
+import { hydrateState } from "@/lib/state/hydration/hydrator";
+import { defaultState } from "@/lib/state/default-state";
+import type { AppState } from "@/lib/state/store";
 import { taskId, workflowId, workspaceId } from "@/lib/types/ids";
 import type { WorkflowSnapshot } from "@/lib/types/http";
 import { partitionWipTasks } from "@/lib/kanban/wip-queue";
@@ -47,6 +52,18 @@ function snapshotWithPendingAction(action: unknown): WorkflowSnapshot {
  };
 }

+const EXECUTOR_ID = "exec-worktree";
+const EXECUTOR_TYPE = "worktree";
+const EXECUTOR_NAME = "Worktree";
+
+function snapshotWithExecutor(): WorkflowSnapshot {
+  const snapshot = snapshotWithPendingAction(undefined);
+  snapshot.tasks[0].primary_executor_id = EXECUTOR_ID;
+  snapshot.tasks[0].primary_executor_type = EXECUTOR_TYPE;
+  snapshot.tasks[0].primary_executor_name = EXECUTOR_NAME;
+  return snapshot;
+}
+
 // eslint-disable-next-line max-lines-per-function -- test describe block, splitting hurts readability
 describe("snapshotToState", () => {
  it("keeps known primary session pending action values", () => {
@@ -115,6 +132,45 @@ describe("snapshotToState", () => {
    expect(state.kanban?.tasks[0]?.statusSummary).toEqual(snapshot.tasks[0].status_summary);
  });

+  it("maps the primary executor binding onto the kanban task", () => {
+    const snapshot = snapshotWithExecutor();
+    snapshot.tasks[0].is_remote_executor = false;
+
+    const state = snapshotToState(snapshot);
+
+    expect(state.kanban?.tasks[0]).toMatchObject({
+      primaryExecutorId: EXECUTOR_ID,
+      primaryExecutorType: EXECUTOR_TYPE,
+      primaryExecutorName: EXECUTOR_NAME,
+      isRemoteExecutor: false,
+    });
+  });
+
+  it("leaves the executor binding unset when the snapshot omits it", () => {
+    // The backend marks every executor field `omitempty`, so a task whose
+    // primary session has not bound an executor yet arrives with the keys
+    // absent rather than null. The mapper must yield undefined here, never
+    // crash and never invent a binding.
+    const state = snapshotToState(snapshotWithPendingAction(undefined));
+
+    expect(state.kanban?.tasks[0]?.primaryExecutorId).toBeUndefined();
+    expect(state.kanban?.tasks[0]?.primaryExecutorType).toBeUndefined();
+    expect(state.kanban?.tasks[0]?.primaryExecutorName).toBeUndefined();
+    expect(state.kanban?.tasks[0]?.isRemoteExecutor).toBe(false);
+  });
+
+  it("leaves an explicitly undefined executor binding unset", () => {
+    // Reviewer-requested wire-contract coverage. JSON omits undefined values,
+    // but typed snapshot fixtures can retain the property; both representations
+    // must produce the same unresolved client state.
+    const snapshot = snapshotWithPendingAction(undefined);
+    snapshot.tasks[0].primary_executor_type = undefined;
+
+    const state = snapshotToState(snapshot);
+
+    expect(state.kanban?.tasks[0]?.primaryExecutorType).toBeUndefined();
+  });
+
  it("preserves workflow step WIP fields", () => {
    const state = snapshotToState({
      workflow: {
@@ -182,3 +238,34 @@ describe("snapshotToState", () => {
    ]);
  });
 });
+
+describe("snapshotToState feeding hydrateState", () => {
+  it("does not blank an already-known executor when a re-hydration lands", () => {
+    // Regression guard for the bug this change fixes, exercised through the
+    // real chain: use-workflow-snapshot calls hydrate(snapshotToState(...)) on
+    // (re)mount, and mergeKanbanTasks replaces the cached task wholesale when
+    // the incoming updatedAt is not older. While snapshotToState dropped the
+    // executor fields, that replacement silently reset primaryExecutorType to
+    // undefined and the "Add folder" control disappeared.
+    const draft = structuredClone(defaultState) as AppState;
+    draft.kanban.tasks = [
+      {
+        id: taskId("task-1"),
+        workflowId: workflowID,
+        workflowStepId: "step-1",
+        title: "Task",
+        position: 0,
+        updatedAt: now,
+        primaryExecutorId: EXECUTOR_ID,
+        primaryExecutorType: EXECUTOR_TYPE,
+        primaryExecutorName: EXECUTOR_NAME,
+      },
+    ] as AppState["kanban"]["tasks"];
+
+    const result = produce(draft, (d: Draft<AppState>) => {
+      hydrateState(d, snapshotToState(snapshotWithExecutor()));
+    });
+
+    expect(result.kanban.tasks[0]?.primaryExecutorType).toBe(EXECUTOR_TYPE);
+  });
+});
@@ -16,6 +16,15 @@ function resolveAutoStartFailed(task: WorkflowSnapshot["tasks"][number]): boolea
  return task.auto_start_failed ?? false;
 }

+function primaryExecutorFields(task: Task) {
+  return {
+    primaryExecutorId: task.primary_executor_id ?? undefined,
+    primaryExecutorType: task.primary_executor_type ?? undefined,
+    primaryExecutorName: task.primary_executor_name ?? undefined,
+    isRemoteExecutor: task.is_remote_executor ?? false,
+  };
+}
+
 export function snapshotToState(snapshot: WorkflowSnapshot): Partial<AppState> {
  // Handle empty snapshot (ephemeral tasks have no workflow)
  if (!snapshot.workflow) {
@@ -64,6 +73,7 @@ export function snapshotToState(snapshot: WorkflowSnapshot): Partial<AppState> {
        })),
        primarySessionId: task.primary_session_id ?? undefined,
        primarySessionState: task.primary_session_state ?? undefined,
+        ...primaryExecutorFields(task),
        primarySessionPendingAction: pickPendingAction(task.primary_session_pending_action),
        taskPendingAction: pickPendingAction(task.task_pending_action),
        foregroundActivity: task.foreground_activity ?? undefined,
@@ -24,6 +24,7 @@
  "addBlocker": "+ Add blocker",
  "addDetailsAboutThisChange": "Add details about this change...",
  "addFolder": "Add folder",
+  "addFolderExecutorUnknown": "Waiting to confirm this task's executor supports folders",
  "addLabel": "Add label",
  "addLabels": "+ Add labels",
  "addMore": "Add more",
@@ -24,6 +24,7 @@
  "addBlocker": "+ Àďď ƀĺōćķēŕ",
  "addDetailsAboutThisChange": "Àďď ďēţàĩĺś àƀōũţ ţĥĩś ćĥàńĝē...",
  "addFolder": "Àďď ƒōĺďēŕ",
+  "addFolderExecutorUnknown": "Ŵàĩţĩńĝ ţō ćōńƒĩŕḿ ţĥĩś ţàśķ'ś ēxēćũţōŕ śũƥƥōŕţś ƒōĺďēŕś",
  "addLabel": "Àďď ĺàƀēĺ",
  "addLabels": "+ Àďď ĺàƀēĺś",
  "addMore": "Àďď ḿōŕē",
@@ -24,6 +24,7 @@
  "addBlocker": "+ Adicionar bloqueio",
  "addDetailsAboutThisChange": "Adicione detalhes sobre esta alteração...",
  "addFolder": "Adicionar pasta",
+  "addFolderExecutorUnknown": "O executor desta tarefa ainda não foi confirmado",
  "addLabel": "Adicionar etiqueta",
  "addLabels": "+ Adicionar etiquetas",
  "addMore": "Adicionar mais",
@@ -24,6 +24,7 @@
  "addBlocker": "+ 添加阻塞项",
  "addDetailsAboutThisChange": "添加此变更的详细说明…",
  "addFolder": "添加文件夹",
+  "addFolderExecutorUnknown": "尚未确认此任务的执行器",
  "addLabel": "添加标签",
  "addLabels": "+ 添加标签",
  "addMore": "添加更多",
@@ -24,6 +24,7 @@
  "addBlocker": "+ 新增阻塞項",
  "addDetailsAboutThisChange": "新增此變更的詳細說明…",
  "addFolder": "新增資料夾",
+  "addFolderExecutorUnknown": "尚未確認此任務的執行器",
  "addLabel": "新增標籤",
  "addLabels": "+ 新增標籤",
  "addMore": "新增更多",
@@ -24,6 +24,7 @@
  "addBlocker": "+ 新增阻塞項",
  "addDetailsAboutThisChange": "新增此變更的詳細說明…",
  "addFolder": "新增資料夾",
+  "addFolderExecutorUnknown": "尚未確認此任務的執行器",
  "addLabel": "新增標籤",
  "addLabels": "+ 新增標籤",
  "addMore": "新增更多",