diff --git a/frontend/src/features/layout/LayoutGrid.refitEpoch.test.tsx b/frontend/src/features/layout/LayoutGrid.refitEpoch.test.tsx
new file mode 100644
index 0000000..12820f4
--- /dev/null
+++ b/frontend/src/features/layout/LayoutGrid.refitEpoch.test.tsx
@@ -0,0 +1,136 @@
+import { useEffect } from "react";
+import { describe, expect, it, vi } from "vitest";
+import { render, screen, waitFor } from "@testing-library/react";
+
+import type { Gateways } from "@/ports";
+import { MockLayoutGateway, MockTerminalGateway } from "@/adapters/mock";
+import { DIProvider } from "@/app/di";
+
+const terminalViewSpy = vi.hoisted(() => vi.fn());
+const terminalMountSpy = vi.hoisted(() => vi.fn());
+const terminalUnmountSpy = vi.hoisted(() => vi.fn());
+
+vi.mock("@/features/terminals", () => ({
+  TerminalView: (props: { refitSignal?: number }) => {
+    terminalViewSpy(props);
+    useEffect(() => {
+      terminalMountSpy();
+      return () => terminalUnmountSpy();
+    }, []);
+    return (
+      <div
+        data-testid="mock-terminal-view"
+        data-refit-signal={String(props.refitSignal)}
+      />
+    );
+  },
+  ResumeConversationPopup: () => null,
+  useWritePortal: () => ({
+    portal: {
+      onHumanData: () => {},
+      isSuspended: () => false,
+      bindHandle: () => {},
+      unbindHandle: () => {},
+    },
+    overlay: false,
+  }),
+}));
+
+import { LayoutGrid } from "./LayoutGrid";
+
+function renderGrid(
+  layout: MockLayoutGateway,
+  props: { projectId: string; cwd: string; layoutId?: string },
+) {
+  const gateways = {
+    layout,
+    terminal: new MockTerminalGateway(),
+  } as unknown as Gateways;
+
+  return render(
+    <DIProvider gateways={gateways}>
+      <LayoutGrid {...props} />
+    </DIProvider>,
+  );
+}
+
+function latestRefitSignal(): number {
+  const lastCall = terminalViewSpy.mock.calls.at(-1);
+  return Number(lastCall?.[0]?.refitSignal ?? -1);
+}
+
+describe("LayoutGrid refit epoch (#4)", () => {
+  it("bumps TerminalView refitSignal after cwd/layout/project transitions", async () => {
+    const layout = new MockLayoutGateway();
+    const { activeId: firstLayoutId } = await layout.listLayouts("p1");
+    const { layoutId: secondLayoutId } = await layout.createLayout("p1", "Second");
+    terminalViewSpy.mockClear();
+    terminalMountSpy.mockClear();
+    terminalUnmountSpy.mockClear();
+
+    const view = renderGrid(layout, {
+      projectId: "p1",
+      cwd: "/same/cwd",
+      layoutId: firstLayoutId,
+    });
+
+    await screen.findByTestId("mock-terminal-view");
+    await waitFor(() => expect(latestRefitSignal()).toBeGreaterThan(0));
+    const initialSignal = latestRefitSignal();
+    expect(terminalMountSpy).toHaveBeenCalledTimes(1);
+
+    view.rerender(
+      <DIProvider
+        gateways={{
+          layout,
+          terminal: new MockTerminalGateway(),
+        } as unknown as Gateways}
+      >
+        <LayoutGrid
+          projectId="p1"
+          cwd="/same/cwd/after-transition"
+          layoutId={firstLayoutId}
+        />
+      </DIProvider>,
+    );
+
+    await waitFor(() => expect(latestRefitSignal()).toBeGreaterThan(initialSignal));
+    const afterCwdSignal = latestRefitSignal();
+    expect(terminalMountSpy).toHaveBeenCalledTimes(1);
+    expect(terminalUnmountSpy).not.toHaveBeenCalled();
+
+    view.rerender(
+      <DIProvider
+        gateways={{
+          layout,
+          terminal: new MockTerminalGateway(),
+        } as unknown as Gateways}
+      >
+        <LayoutGrid
+          projectId="p1"
+          cwd="/same/cwd/after-transition"
+          layoutId={secondLayoutId}
+        />
+      </DIProvider>,
+    );
+
+    await waitFor(() => expect(latestRefitSignal()).toBeGreaterThan(afterCwdSignal));
+    const afterLayoutSwitchSignal = latestRefitSignal();
+
+    view.rerender(
+      <DIProvider
+        gateways={{
+          layout,
+          terminal: new MockTerminalGateway(),
+        } as unknown as Gateways}
+      >
+        <LayoutGrid projectId="p2" cwd="/same/cwd" />
+      </DIProvider>,
+    );
+
+    await waitFor(() =>
+      expect(latestRefitSignal()).toBeGreaterThan(afterLayoutSwitchSignal),
+    );
+    expect(terminalMountSpy).toHaveBeenCalled();
+  });
+});
diff --git a/frontend/src/features/layout/LayoutGrid.tsx b/frontend/src/features/layout/LayoutGrid.tsx
index 7ae6c5c..86709e0 100644
--- a/frontend/src/features/layout/LayoutGrid.tsx
+++ b/frontend/src/features/layout/LayoutGrid.tsx
@@ -97,6 +97,11 @@ export function LayoutGrid({
 }: LayoutGridProps) {
   const vm = useLayout(projectId, layoutId);
   const work = useProjectWorkState(projectId);
+  const [refitEpoch, setRefitEpoch] = useState(0);
+
+  useEffect(() => {
+    setRefitEpoch((epoch) => epoch + 1);
+  }, [projectId, layoutId, cwd, vm.layoutVersion]);
 
   if (!vm.layout) {
     return (
@@ -129,6 +134,7 @@ export function LayoutGrid({
         projectId={projectId}
         workState={work.state}
         refreshWorkState={work.refresh}
+        refitSignal={refitEpoch}
         onOpenConversation={onOpenConversation}
         onOpenPluginsSettings={onOpenPluginsSettings}
       />
@@ -145,6 +151,7 @@ interface NodeViewProps {
   projectId: string;
   workState: ProjectWorkState | null;
   refreshWorkState: () => Promise<void>;
+  refitSignal: number;
   onOpenConversation?: (conversationId: string) => void;
   onOpenPluginsSettings?: () => void;
 }
@@ -157,6 +164,7 @@ function NodeView({
   projectId,
   workState,
   refreshWorkState,
+  refitSignal,
   onOpenConversation,
   onOpenPluginsSettings,
 }: NodeViewProps) {
@@ -190,6 +198,7 @@ function NodeView({
           projectId={projectId}
           workState={workState}
           refreshWorkState={refreshWorkState}
+          refitSignal={refitSignal}
           onOpenConversation={onOpenConversation}
         />
       );
@@ -202,6 +211,7 @@ function NodeView({
           projectId={projectId}
           workState={workState}
           refreshWorkState={refreshWorkState}
+          refitSignal={refitSignal}
           onOpenConversation={onOpenConversation}
           onOpenPluginsSettings={onOpenPluginsSettings}
         />
@@ -215,6 +225,7 @@ function NodeView({
           projectId={projectId}
           workState={workState}
           refreshWorkState={refreshWorkState}
+          refitSignal={refitSignal}
           onOpenConversation={onOpenConversation}
           onOpenPluginsSettings={onOpenPluginsSettings}
         />
@@ -234,6 +245,7 @@ interface LeafViewProps {
   projectId: string;
   workState: ProjectWorkState | null;
   refreshWorkState: () => Promise<void>;
+  refitSignal: number;
   onOpenConversation?: (conversationId: string) => void;
 }
 
@@ -315,6 +327,7 @@ function LeafView({
   projectId,
   workState,
   refreshWorkState,
+  refitSignal,
   onOpenConversation,
 }: LeafViewProps) {
   // A cell can be closed only when it lives inside a (binary) split: closing it
@@ -950,7 +963,7 @@ function LeafView({
           onSessionId={(sid) => void vm.setSession(id, sid)}
           agentMode={agentId != null}
           portal={agentId != null ? portal : undefined}
-          refitSignal={vm.layoutVersion}
+          refitSignal={refitSignal}
         />
         {/* Write-portal overlay (ARCHITECTURE §20.3 step b/e): while a delegation
             is being injected into the agent's PTY, a grey veil with a centred
@@ -1185,6 +1198,7 @@ interface SplitViewProps {
   projectId: string;
   workState: ProjectWorkState | null;
   refreshWorkState: () => Promise<void>;
+  refitSignal: number;
   onOpenConversation?: (conversationId: string) => void;
   onOpenPluginsSettings?: () => void;
 }
@@ -1196,6 +1210,7 @@ function SplitView({
   projectId,
   workState,
   refreshWorkState,
+  refitSignal,
   onOpenConversation,
   onOpenPluginsSettings,
 }: SplitViewProps) {
@@ -1241,6 +1256,7 @@ function SplitView({
               projectId={projectId}
               workState={workState}
               refreshWorkState={refreshWorkState}
+              refitSignal={refitSignal}
               onOpenConversation={onOpenConversation}
               onOpenPluginsSettings={onOpenPluginsSettings}
               parentSplit={{
@@ -1336,6 +1352,7 @@ interface GridViewProps {
   projectId: string;
   workState: ProjectWorkState | null;
   refreshWorkState: () => Promise<void>;
+  refitSignal: number;
   onOpenConversation?: (conversationId: string) => void;
   onOpenPluginsSettings?: () => void;
 }
@@ -1347,6 +1364,7 @@ function GridView({
   projectId,
   workState,
   refreshWorkState,
+  refitSignal,
   onOpenConversation,
   onOpenPluginsSettings,
 }: GridViewProps) {
@@ -1388,6 +1406,7 @@ function GridView({
             projectId={projectId}
             workState={workState}
             refreshWorkState={refreshWorkState}
+            refitSignal={refitSignal}
             onOpenConversation={onOpenConversation}
             onOpenPluginsSettings={onOpenPluginsSettings}
           />