diff --git a/packages/app/e2e/browser/bottom-sheet-reopen.spec.ts b/packages/app/e2e/browser/bottom-sheet-reopen.spec.ts
index 89ee10af22..bc65ae65de 100644
--- a/packages/app/e2e/browser/bottom-sheet-reopen.spec.ts
+++ b/packages/app/e2e/browser/bottom-sheet-reopen.spec.ts
@@ -89,9 +89,11 @@ async function dismissStackedModelPickerWithBackdrop(page: Page) {
     .getByTestId("agent-controls-settings-list")
     .getByRole("button", { name: /Select model/ })
     .click();
-  await expect(page.getByTestId("agent-controls-model-browser-sheet")).toBeVisible();
+  await expect(page.getByTestId("agent-controls-model-browser-sheet")).toBeInViewport();
   await page.mouse.click(MOBILE_VIEWPORT.width / 2, 24);
-  await expect(page.getByTestId("agent-controls-model-browser-sheet")).not.toBeVisible();
+  // In CI, Gorhom retains the dismissed sheet below the viewport.
+  // Dismissal is complete when it leaves the displayed surface.
+  await expect(page.getByTestId("agent-controls-model-browser-sheet")).not.toBeInViewport();
   await expect(page.getByTestId("agent-controls-model-sheet")).toBeVisible();
   await expect(page.getByTestId("agent-controls-settings-list")).toBeVisible();
 }
@@ -139,7 +141,7 @@ test.describe("mobile bottom sheet reopen", () => {
         await expect(sheet).toBeVisible();
         await expect(page.getByTestId("agent-controls-settings-list")).toBeVisible();
         await expect(page.getByTestId("agent-controls-model")).toContainText("Ten second stream");
-        await expect(page.getByTestId("agent-controls-model-browser-sheet")).not.toBeVisible();
+        await expect(page.getByTestId("agent-controls-model-browser-sheet")).not.toBeInViewport();
       });
     } finally {
       await session.cleanup();
diff --git a/packages/app/e2e/browser/plugin-popover.spec.ts b/packages/app/e2e/browser/plugin-popover.spec.ts
new file mode 100644
index 0000000000..8ce3b35513
--- /dev/null
+++ b/packages/app/e2e/browser/plugin-popover.spec.ts
@@ -0,0 +1,47 @@
+import { expect, test, type Page } from "../support/fixtures";
+import { composerLocator, submitMessageWithButton } from "../support/helpers/composer";
+import { seedMockAgentWorkspace, openAgentRoute } from "../support/helpers/mock-agent";
+import { withPopoverTimelinePlugin } from "../support/helpers/plugin-timeline";
+
+async function openPreviewWhileTyping(page: Page): Promise<void> {
+  await composerLocator(page).focus();
+  await page.getByRole("button", { name: "Hover plugin preview", exact: true }).hover();
+  await expect(page.getByRole("dialog", { name: "Plugin preview" })).toBeVisible();
+  await expect(composerLocator(page)).toBeFocused();
+}
+
+async function dismissPreview(page: Page): Promise<void> {
+  await page.keyboard.press("Escape");
+  await expect(page.getByRole("dialog", { name: "Plugin preview" })).not.toBeVisible();
+}
+
+test("Escape dismisses a plugin preview before interrupting the agent", async ({ page }) => {
+  test.setTimeout(120_000);
+  const agent = await seedMockAgentWorkspace({
+    repoPrefix: "plugin-popover-",
+    title: "Plugin preview keyboard regression",
+    model: "e2e-fast-stream",
+  });
+  try {
+    await withPopoverTimelinePlugin(async () => {
+      await openAgentRoute(page, agent);
+      await submitMessageWithButton(page, "Show the plugin preview.");
+      await agent.client.waitForFinish(agent.agentId, 30_000);
+      await expect(page.getByRole("button", { name: "Hover plugin preview" })).toBeVisible();
+      await submitMessageWithButton(page, "withhold synthetic user message until interrupted");
+      const stop = page.getByRole("button", { name: "Stop agent", exact: true });
+      await expect(stop).toBeVisible();
+
+      await openPreviewWhileTyping(page);
+      await dismissPreview(page);
+      await expect(stop).toBeVisible();
+      await expect(composerLocator(page)).toBeFocused();
+
+      await page.keyboard.press("Escape");
+      await expect(stop).not.toBeVisible();
+      await agent.client.waitForFinish(agent.agentId, 15_000);
+    });
+  } finally {
+    await agent.cleanup();
+  }
+});
diff --git a/packages/app/e2e/support/helpers/plugin-timeline.ts b/packages/app/e2e/support/helpers/plugin-timeline.ts
index 8ad7e0a632..8b0f680e2d 100644
--- a/packages/app/e2e/support/helpers/plugin-timeline.ts
+++ b/packages/app/e2e/support/helpers/plugin-timeline.ts
@@ -231,3 +231,46 @@ export async function attachPromptTimelineEvidence(page: Page, info: TestInfo):
     contentType: "image/png",
   });
 }
+
+const POPOVER_CLIENT_SOURCE = `import React, { useEffect, useRef } from "react";
+import { z } from "zod";
+
+function Preview() {
+  const panel = useRef(null);
+  useEffect(() => {
+    const close = (event) => {
+      if (event.key === "Escape" && panel.current.matches(":popover-open")) {
+        panel.current.hidePopover();
+      }
+    };
+    document.addEventListener("keydown", close, true);
+    return () => document.removeEventListener("keydown", close, true);
+  }, []);
+  return <div>
+    <button onMouseEnter={() => panel.current.showPopover()}>Hover plugin preview</button>
+    <div ref={panel} popover="manual" role="dialog" aria-label="Plugin preview">Plugin hover preview</div>
+  </div>;
+}
+
+export default function contribute(client) {
+  client.addTimelineTransformer({
+    id: "preview", query: { itemType: "user_message" },
+    transform({ item }) {
+      if (item.text !== "Show the plugin preview.") return;
+      return { items: [{ type: "plugin", kind: "preview", version: 1, data: {} }] };
+    },
+  });
+  client.addTimelineRenderer({
+    kind: "preview", version: 1, schema: z.object({}), Component: Preview,
+  });
+  return () => {};
+}`;
+
+/** Installs a timeline preview that owns Escape through the DOM Popover API. */
+export async function withPopoverTimelinePlugin(run: () => Promise<void>): Promise<void> {
+  await withDirectoryPlugin({
+    pluginId: "timeline-popover-e2e",
+    source: POPOVER_CLIENT_SOURCE,
+    run,
+  });
+}
diff --git a/packages/app/src/hooks/use-keyboard-shortcuts.ts b/packages/app/src/hooks/use-keyboard-shortcuts.ts
index d723b5be04..6f332b0a98 100644
--- a/packages/app/src/hooks/use-keyboard-shortcuts.ts
+++ b/packages/app/src/hooks/use-keyboard-shortcuts.ts
@@ -40,7 +40,7 @@ import {
   navigateToLastWorkspace,
   useActiveWorkspaceSelection,
 } from "@/stores/navigation-active-workspace-store";
-import { dispatchTopWebOverlayKeyDown } from "@/lib/overlay-root";
+import { dispatchTopWebOverlayKeyDown, keyBelongsToDomPopover } from "@/lib/overlay-root";
 
 export function useKeyboardShortcuts({
   enabled,
@@ -321,6 +321,10 @@ export function useKeyboardShortcuts({
       return;
     }
 
+    if (keyBelongsToDomPopover(event)) {
+      return;
+    }
+
     // During IME composition, Enter confirms the candidate selection and must
     // not route through global shortcuts like message send.
     if (isImeComposingKeyboardEvent(event)) {
diff --git a/packages/app/src/lib/overlay-root.browser.test.tsx b/packages/app/src/lib/overlay-root.browser.test.tsx
index a21403dd8d..bd20d2aeeb 100644
--- a/packages/app/src/lib/overlay-root.browser.test.tsx
+++ b/packages/app/src/lib/overlay-root.browser.test.tsx
@@ -2,7 +2,11 @@ import React, { type RefCallback } from "react";
 import { flushSync } from "react-dom";
 import { createRoot, type Root } from "react-dom/client";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
-import { useWebOverlayRegistration } from "./overlay-root";
+import {
+  hasOpenDomPopover,
+  keyBelongsToDomPopover,
+  useWebOverlayRegistration,
+} from "./overlay-root";
 
 function nextFrame(): Promise<void> {
   return new Promise((resolve) => requestAnimationFrame(() => resolve()));
@@ -68,3 +72,35 @@ describe("useWebOverlayRegistration in the browser", () => {
     expect(openerFocusCalls).toBe(1);
   });
 });
+
+describe("hasOpenDomPopover", () => {
+  afterEach(() => {
+    document.body.replaceChildren();
+  });
+
+  it("is true only while a popover is shown", () => {
+    const panel = document.createElement("div");
+    panel.setAttribute("popover", "manual");
+    document.body.append(panel);
+    expect(hasOpenDomPopover()).toBe(false);
+    panel.showPopover();
+    expect(hasOpenDomPopover()).toBe(true);
+    panel.hidePopover();
+    expect(hasOpenDomPopover()).toBe(false);
+  });
+});
+
+describe("Escape with a plugin popover open", () => {
+  afterEach(() => {
+    document.body.replaceChildren();
+  });
+
+  it("leaves other keys to the shortcuts while a popover is open", () => {
+    const panel = document.createElement("div");
+    panel.setAttribute("popover", "manual");
+    document.body.append(panel);
+    panel.showPopover();
+    expect(keyBelongsToDomPopover({ key: "Enter" })).toBe(false);
+    expect(keyBelongsToDomPopover({ key: "Escape" })).toBe(true);
+  });
+});
diff --git a/packages/app/src/lib/overlay-root.ts b/packages/app/src/lib/overlay-root.ts
index 9ffd81725f..d1ab0b9787 100644
--- a/packages/app/src/lib/overlay-root.ts
+++ b/packages/app/src/lib/overlay-root.ts
@@ -112,6 +112,31 @@ export function hasActiveWebOverlay(): boolean {
   return getTopWebOverlay() !== undefined;
 }
 
+/**
+ * True while an element shown with the Popover API is open. Such a layer
+ * floats above the app like a registered overlay but lives outside the
+ * registry: plugins draw their panels this way, since they cannot register.
+ */
+export function hasOpenDomPopover(): boolean {
+  if (typeof document === "undefined") return false;
+  try {
+    return document.querySelector(":popover-open") !== null;
+  } catch {
+    // An engine without the Popover API rejects the selector, and has none open.
+    return false;
+  }
+}
+
+/**
+ * Whether a key belongs to an open popover rather than to the app's shortcuts.
+ * An open popover (a plugin's panel) is the top layer and closes on its own
+ * Escape listener, which runs after the shortcut engine's capture listener:
+ * Escape must not also interrupt the running agent.
+ */
+export function keyBelongsToDomPopover(event: Pick<KeyboardEvent, "key">): boolean {
+  return event.key === "Escape" && hasOpenDomPopover();
+}
+
 function getFocusableElements(scope: HTMLElement): HTMLElement[] {
   const selector = [
     "a[href]",