diff --git a/packages/app/e2e/mobile/workspace-update-freeze/README.md b/packages/app/e2e/mobile/workspace-update-freeze/README.md
new file mode 100644
index 0000000000..2141004bec
--- /dev/null
+++ b/packages/app/e2e/mobile/workspace-update-freeze/README.md
@@ -0,0 +1,55 @@
+# Android input delay diagnostic
+
+Diagnostic evidence for https://github.com/getpaseo/paseo/issues/4408, not a fix or a CI test.
+
+Observed with the published Android 0.11.4 APK on an Android 16 emulator and a main
+daemon at 7c7b6555f17a88cffddf484129cd04ad79704f59. The fixture has 400 active
+workspaces sharing one checkout, plus a synthetic 110-turn conversation and a
+five-minute mock-provider stream. Clean/dirty transitions emitted 400 workspace
+updates each. The JavaScript thread reached 96–100% CPU, and tapping Open menu
+did not expose Close sidebar within five seconds. The same process stayed alive.
+
+This combines the many-workspace and streaming reports. It does not isolate which
+work causes the delay, reproduce an allocation crash, or establish that the
+contributor's byte-counting optimization fixes it. An emulator is not the affected
+physical phone. No forced memory pressure, forced garbage collection, or fake
+client responses are used. The daemon's existing mock provider supplies synthetic
+agent output through the normal transport.
+
+## Run
+
+Use a disposable emulator with the published app installed and agent-device
+0.20.3 or later. Preserve its previous state before changing its app installation.
+Build the repository's server dependencies first. All commands below run from
+the repository root in a disposable worktree.
+
+1. Start `npx tsx packages/app/e2e/mobile/workspace-update-freeze/fixture.ts`.
+   It writes an isolated home under `.dev/workspace-update-freeze`, starts an
+   isolated daemon, and exposes it on local TCP port 45151. Do not use an existing
+   daemon or point this script at real data.
+2. Forward that port to the emulator, open the app with an agent-device session,
+   and add a direct connection to that isolated daemon. Open the sidebar and
+   verify that the Android reproduction project and workspace rows are visible.
+3. Start `npx tsx packages/app/e2e/mobile/workspace-update-freeze/stream.ts`.
+   Wait for `HISTORY_READY`. The script writes the agent ID to
+   `.dev/workspace-update-freeze/history-ready` and starts the five-minute stream.
+4. Open `paseo://h/diag515a/agent/<agent-id>` with agent-device, using the generated
+   ID. Dismiss the notification prompt if present. Verify that the agent's text
+   and Stop agent button are visible, then scroll the conversation.
+5. Start `node packages/app/e2e/mobile/workspace-update-freeze/toggle.mjs` in a
+   separate terminal. It toggles the fixture's tracked file every three seconds
+   for 90 seconds. `events.json` records workspace updates observed by an actual
+   subscribed daemon client; initial subscription updates are included.
+6. While the toggles and stream are active, run:
+
+   ```sh
+   node packages/app/e2e/mobile/workspace-update-freeze/android.mjs <device-session>
+   ```
+
+   It taps Open menu and requires Close sidebar within five seconds. The observed
+   failure was a timeout for Close sidebar while Open menu remained visible.
+   This asserts an input delay, not an application crash or its root cause.
+
+Stop the fixture with SIGTERM to close its client, proxy, and isolated daemon.
+Close the agent-device session and restore the emulator's prior state afterward.
+Do not interpret a passing run as disproving the physical-device reports.
diff --git a/packages/app/e2e/mobile/workspace-update-freeze/android.mjs b/packages/app/e2e/mobile/workspace-update-freeze/android.mjs
new file mode 100644
index 0000000000..c3c658917c
--- /dev/null
+++ b/packages/app/e2e/mobile/workspace-update-freeze/android.mjs
@@ -0,0 +1,16 @@
+import { execFileSync } from "node:child_process";
+
+const session = process.argv[2];
+if (!session) throw new Error("Pass the agent-device session connected to the Android fixture");
+
+function device(...args) {
+  return execFileSync("agent-device", [...args, "--session", session], {
+    encoding: "utf8",
+    stdio: "inherit",
+    timeout: 30_000,
+  });
+}
+
+device("wait", 'label="Open menu"', "5000");
+device("press", 'label="Open menu"', "--settle");
+device("wait", 'label="Close sidebar"', "5000");
diff --git a/packages/app/e2e/mobile/workspace-update-freeze/fixture.ts b/packages/app/e2e/mobile/workspace-update-freeze/fixture.ts
new file mode 100644
index 0000000000..5a20421d11
--- /dev/null
+++ b/packages/app/e2e/mobile/workspace-update-freeze/fixture.ts
@@ -0,0 +1,107 @@
+import type { SessionOutboundMessage } from "@getpaseo/protocol/messages";
+import { startIsolatedHostDaemon } from "../../support/helpers/isolated-host-daemon";
+import { connectDaemonClient } from "../../support/helpers/daemon-client-loader";
+import { mkdir, writeFile } from "node:fs/promises";
+import { execFileSync } from "node:child_process";
+import path from "node:path";
+import net from "node:net";
+
+interface FixtureClient {
+  connect(): Promise<void>;
+  close(): Promise<void>;
+  fetchWorkspaces(options: {
+    page: { limit: number };
+    subscribe: Record<string, never>;
+  }): Promise<{ entries: unknown[] }>;
+  subscribeRawMessages(handler: (message: SessionOutboundMessage) => void): () => void;
+}
+
+async function main() {
+  process.env.E2E_METRO_PORT = "8098";
+  const root = path.resolve(".dev/workspace-update-freeze");
+  const cwd = path.join(root, "repo");
+  const home = path.join(root, "home");
+  await mkdir(cwd, { recursive: true });
+  await mkdir(home + "/projects", { recursive: true });
+  for (const args of [
+    ["init", "-b", "main"],
+    ["config", "user.name", "Repro"],
+    ["config", "user.email", "repro@example.com"],
+  ])
+    execFileSync("git", args, { cwd });
+  await writeFile(cwd + "/README.md", "initial\n");
+  execFileSync("git", ["add", "README.md"], { cwd });
+  execFileSync("git", ["commit", "--allow-empty", "-m", "initial"], { cwd });
+  const date = "2026-03-01T00:00:00.000Z";
+  const project = {
+    projectId: "prj_diag515a",
+    rootPath: cwd,
+    kind: "git",
+    displayName: "Android reproduction",
+    projectKey: null,
+    customName: null,
+    customIconRevision: null,
+    createdAt: date,
+    updatedAt: date,
+    archivedAt: null,
+  };
+  const workspaces = Array.from({ length: 400 }, (_, i) => ({
+    workspaceId: `wks_diag515a_${i}`,
+    projectId: project.projectId,
+    cwd,
+    kind: "directory",
+    displayName: `Workspace ${String(i).padStart(3, "0")}`,
+    title: null,
+    branch: null,
+    worktreeRoot: null,
+    baseBranch: "main",
+    isPaseoOwnedWorktree: false,
+    mainRepoRoot: cwd,
+    createdAt: date,
+    updatedAt: date,
+    archivedAt: null,
+    autoArchivedChangeRequestUrl: null,
+    pinnedAt: null,
+  }));
+  await writeFile(home + "/projects/projects.json", JSON.stringify([project]));
+  await writeFile(home + "/projects/workspaces.json", JSON.stringify(workspaces));
+  const daemon = await startIsolatedHostDaemon("diag515a", { paseoHome: home, preserveHome: true });
+  const client = await connectDaemonClient<FixtureClient>({
+    clientIdPrefix: "diag515a",
+    port: daemon.port,
+  });
+  const events: { at: number; payload: unknown }[] = [];
+  client.subscribeRawMessages((m) => {
+    if (m.type === "workspace_update") events.push({ at: Date.now(), payload: m.payload });
+  });
+  const initial = await client.fetchWorkspaces({ page: { limit: 200 }, subscribe: {} });
+  console.log("INITIAL", initial.entries.length);
+  const proxy = net.createServer((socket) => {
+    const up = net.connect(daemon.port, "127.0.0.1");
+    socket.pipe(up);
+    up.pipe(socket);
+    socket.on("error", () => up.destroy());
+    up.on("error", () => socket.destroy());
+  });
+  await new Promise<void>((resolve) => proxy.listen(45151, "127.0.0.1", resolve));
+  await writeFile(
+    root + "/ready.json",
+    JSON.stringify({ port: daemon.port, cwd, pid: daemon.getPid() }),
+  );
+  console.log("READY", daemon.port);
+  const timer = setInterval(async () => {
+    await writeFile(root + "/events.json", JSON.stringify(events));
+  }, 1000);
+  process.on("SIGTERM", async () => {
+    clearInterval(timer);
+    proxy.close();
+    await client.close();
+    await daemon.close();
+    process.exit(0);
+  });
+  await new Promise(() => {});
+}
+main().catch((e) => {
+  console.error(e);
+  process.exit(1);
+});
diff --git a/packages/app/e2e/mobile/workspace-update-freeze/stream.ts b/packages/app/e2e/mobile/workspace-update-freeze/stream.ts
new file mode 100644
index 0000000000..28cb47d5d1
--- /dev/null
+++ b/packages/app/e2e/mobile/workspace-update-freeze/stream.ts
@@ -0,0 +1,41 @@
+import type { SeedDaemonClient } from "../../support/helpers/seed-client";
+import { connectDaemonClient } from "../../support/helpers/daemon-client-loader";
+import { readFile, writeFile } from "node:fs/promises";
+async function main() {
+  const { port, cwd } = JSON.parse(
+    await readFile(".dev/workspace-update-freeze/ready.json", "utf8"),
+  );
+  const client = await connectDaemonClient<SeedDaemonClient>({
+    clientIdPrefix: "stream515a",
+    port,
+  });
+  try {
+    const agent = await client.createAgent({
+      provider: "mock",
+      cwd,
+      workspaceId: "wks_diag515a_0",
+      title: "Android stream reproduction",
+      modeId: "load-test",
+      model: "five-minute-stream",
+    });
+    await writeFile(".dev/workspace-update-freeze/agent.json", JSON.stringify(agent));
+    for (let i = 0; i < 110; i++) {
+      await client.sendAgentMessage(
+        agent.id,
+        `history ${i}: emit 1 coalesced agent stream updates`,
+      );
+      await client.waitForFinish(agent.id, 15000);
+    }
+    console.log("HISTORY_READY", agent.id);
+    await writeFile(".dev/workspace-update-freeze/history-ready", agent.id);
+    await client.sendAgentMessage(agent.id, "Stream a realistic long answer with code blocks.");
+    await client.waitForFinish(agent.id, 360000);
+    console.log("FINISHED");
+  } finally {
+    await client.close();
+  }
+}
+main().catch((e) => {
+  console.error(e);
+  process.exit(1);
+});
diff --git a/packages/app/e2e/mobile/workspace-update-freeze/toggle.mjs b/packages/app/e2e/mobile/workspace-update-freeze/toggle.mjs
new file mode 100644
index 0000000000..06be7206d2
--- /dev/null
+++ b/packages/app/e2e/mobile/workspace-update-freeze/toggle.mjs
@@ -0,0 +1,9 @@
+import { readFile, writeFile } from "node:fs/promises";
+import path from "node:path";
+
+const root = path.resolve(".dev/workspace-update-freeze");
+const { cwd } = JSON.parse(await readFile(path.join(root, "ready.json"), "utf8"));
+for (let index = 0; index < 30; index += 1) {
+  await writeFile(path.join(cwd, "README.md"), index % 2 ? "changed first\n" : "initial\n");
+  await new Promise((resolve) => setTimeout(resolve, 3000));
+}