diff --git a/frontend-modern/browser-tests/README.md b/frontend-modern/browser-tests/README.md
index 17e8e503b..91101484b 100644
--- a/frontend-modern/browser-tests/README.md
+++ b/frontend-modern/browser-tests/README.md
@@ -21,3 +21,37 @@ This covers #1869's refresh stability at the coverage-table boundary. It does
 **not** qualify the full application resource provider/WebSocket path, PBS drawer,
 By date view, virtualised large tables, Settings editing, or Brave. A passing
 result is not grounds to close #1869 or claim the reported top-of-page jump fixed.
+
+## Application refresh boundary
+
+```sh
+pulse-heavy-run -- node scripts/check-backup-app-refresh.mjs
+pulse-heavy-run -- env PULSE_BROWSER_WIDTH=390 node scripts/check-backup-app-refresh.mjs
+```
+
+This separate runner loads the actual application entry point, authentication
+bootstrap, router, scoped/paginated resource queries, WebSocket store and PBS
+resource drawer. Authentication and all API/socket data are synthetic; no live
+Pulse server or credentials are used. The browser blocks off-origin HTTP traffic.
+It supplies 240 workloads and a hybrid PBS resource with a metrics-history target.
+Three replacement `rawData` frames per view change rendered names, rather than
+merely waiting on a timer with unchanged content.
+
+Assertions cover:
+- Coverage: fewer rendered rows than the inventory (windowing enabled), non-zero
+  scroll, expanded restore evidence, focused expansion button and route retained.
+- By date: changed workload name, non-zero scroll, focused navigation link and route
+  retained. This view has no per-artifact expansion toggle.
+- PBS: real History panel remains visible and selected, with its tab focused and
+  route/scroll retained while the PBS name changes. Its baseline scroll is zero;
+  this checks drawer state, not a non-zero drawer-scroll regression.
+- No uncaught page errors or error-level browser console messages.
+
+Printed samples record scroll offsets and active controls. The fixed 500ms waits
+allow initial layout/scroll synchronisation; each refresh waits for changed text.
+The backup artifact HTTP payload itself is static after initial loading: this is
+resource-provider/socket replacement qualification, not backup API refetch proof.
+Narrow-width interaction is keyboard-driven, not touch or Brave qualification.
+The test does not cover Settings Manage editing, Authentication strategy selection,
+expansion padding, arbitrary inventory churn/reordering, or a deployed release.
+Passing is not grounds to close the mixed report #1869.
diff --git a/frontend-modern/browser-tests/app-refresh-verification.json b/frontend-modern/browser-tests/app-refresh-verification.json
new file mode 100644
index 000000000..3b913bf1c
--- /dev/null
+++ b/frontend-modern/browser-tests/app-refresh-verification.json
@@ -0,0 +1,187 @@
+{
+  "version": 1,
+  "verified_at": "2026-09-05T00:55:39.636242+00:00",
+  "application_source_sha": "0c4486102e918a6800fb317166232224fd092a0d",
+  "runner": "scripts/check-backup-app-refresh.mjs",
+  "runner_sha256": "0b1868aa9f2f288fb07153e10abb3622140357a4c1600d1ed40b59f1c3b22b3d",
+  "result": "passed",
+  "environment": "Headless Playwright Chromium; synthetic scoped REST and replacement WebSocket snapshots; actual application entry point",
+  "runs": [
+    {
+      "viewport": {
+        "width": 1440,
+        "height": 900
+      },
+      "coverage": {
+        "baseline": {
+          "y": 775,
+          "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+        },
+        "samples": [
+          {
+            "generation": 1,
+            "y": 775,
+            "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+          },
+          {
+            "generation": 2,
+            "y": 775,
+            "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+          },
+          {
+            "generation": 3,
+            "y": 775,
+            "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+          }
+        ],
+        "visibleCoverageRows": 140,
+        "pageErrors": [],
+        "consoleErrors": []
+      },
+      "other_views": [
+        {
+          "view": "date",
+          "baseline": {
+            "y": 989,
+            "url": "http://127.0.0.1:5198/proxmox/backups/date",
+            "active": "By date"
+          },
+          "samples": [
+            {
+              "y": 989,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "By date"
+            },
+            {
+              "y": 989,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "By date"
+            },
+            {
+              "y": 989,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "By date"
+            }
+          ]
+        },
+        {
+          "view": "PBS History",
+          "baseline": {
+            "y": 0,
+            "url": "http://127.0.0.1:5198/proxmox/backups/date",
+            "active": "History"
+          },
+          "samples": [
+            {
+              "y": 0,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "History"
+            },
+            {
+              "y": 0,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "History"
+            },
+            {
+              "y": 0,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "History"
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "viewport": {
+        "width": 390,
+        "height": 900
+      },
+      "coverage": {
+        "baseline": {
+          "y": 636,
+          "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+        },
+        "samples": [
+          {
+            "generation": 1,
+            "y": 636,
+            "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+          },
+          {
+            "generation": 2,
+            "y": 636,
+            "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+          },
+          {
+            "generation": 3,
+            "y": 636,
+            "url": "http://127.0.0.1:5198/proxmox/backups/coverage"
+          }
+        ],
+        "visibleCoverageRows": 36,
+        "pageErrors": [],
+        "consoleErrors": []
+      },
+      "other_views": [
+        {
+          "view": "date",
+          "baseline": {
+            "y": 900,
+            "url": "http://127.0.0.1:5198/proxmox/backups/date",
+            "active": "By date"
+          },
+          "samples": [
+            {
+              "y": 900,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "By date"
+            },
+            {
+              "y": 900,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "By date"
+            },
+            {
+              "y": 900,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "By date"
+            }
+          ]
+        },
+        {
+          "view": "PBS History",
+          "baseline": {
+            "y": 0,
+            "url": "http://127.0.0.1:5198/proxmox/backups/date",
+            "active": "History"
+          },
+          "samples": [
+            {
+              "y": 0,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "History"
+            },
+            {
+              "y": 0,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "History"
+            },
+            {
+              "y": 0,
+              "url": "http://127.0.0.1:5198/proxmox/backups/date",
+              "active": "History"
+            }
+          ]
+        }
+      ]
+    }
+  ],
+  "limitations": [
+    "Not a deployed release or reporter Brave retest; Brave executable not available on PATH",
+    "Keyboard interaction at narrow width, not touch",
+    "Static backup-artifact API after initial load; replacement resource snapshots only",
+    "PBS History baseline scroll is zero; no non-zero drawer-scroll proof",
+    "No Settings Manage editing, Authentication strategy or expansion-padding qualification",
+    "No full repository suite or build run; no product code changed"
+  ]
+}
diff --git a/scripts/check-backup-app-refresh.mjs b/scripts/check-backup-app-refresh.mjs
new file mode 100644
index 000000000..7f0deb838
--- /dev/null
+++ b/scripts/check-backup-app-refresh.mjs
@@ -0,0 +1,318 @@
+// Run with pulse-heavy-run -- node scripts/check-backup-app-refresh.mjs
+// Full application shell with synthetic API and WebSocket snapshots; no live deployment.
+import { createServer } from "../frontend-modern/node_modules/vite/dist/node/index.js";
+import { chromium, expect } from "@playwright/test";
+import { fileURLToPath } from "node:url";
+
+const root = fileURLToPath(new URL("../frontend-modern", import.meta.url));
+process.chdir(root); // PostCSS/Tailwind resolve their config from the frontend root.
+const server = await createServer({
+  root,
+  configFile: `${root}/vite.config.ts`,
+  server: { host: "127.0.0.1", port: 5198, strictPort: true },
+});
+let browser;
+try {
+  await server.listen();
+  browser = await chromium.launch({ headless: true });
+  const page = await browser.newPage({
+    viewport: {
+      width: Number(process.env.PULSE_BROWSER_WIDTH || 1440),
+      height: 900,
+    },
+  });
+  // Never allow this synthetic qualification to contact a real service.
+  await page.route("**/*", (route) => {
+    const url = new URL(route.request().url());
+    if (url.origin !== "http://127.0.0.1:5198") return route.abort();
+    return route.continue();
+  });
+  const errors = [];
+  const consoleErrors = [];
+  page.on("pageerror", (error) => errors.push(error.message));
+  page.on("console", (message) => {
+    if (message.type() === "error") consoleErrors.push(message.text());
+  });
+  page.on("requestfailed", (request) =>
+    console.error(request.url(), request.failure()),
+  );
+  let generation = 0;
+  const workloads = () =>
+    Array.from({ length: 240 }, (_, index) => ({
+      id: `ct-${112 + index}`,
+      type: "system-container",
+      name: `guest-${String(index).padStart(2, "0")}-snapshot-${generation}`,
+      displayName: `guest-${String(index).padStart(2, "0")}-snapshot-${generation}`,
+      platformId: "pve-a",
+      platformType: "proxmox-pve",
+      sourceType: "api",
+      status: "running",
+      lastSeen: Date.now(),
+      proxmox: { vmid: 112 + index, node: "pve-a", instance: "pve-a" },
+    }));
+  const pbs = () => ({
+    id: "pbs-1",
+    type: "pbs",
+    name: `pbs-main-snapshot-${generation}`,
+    displayName: "PBS Main",
+    platformId: "pbs-main",
+    platformType: "proxmox-pbs",
+    sourceType: "hybrid",
+    metricsTarget: { resourceType: "agent", resourceId: "agent-pbs-1" },
+    agent: { agentId: "agent-pbs-1", hostname: "pbs-main" },
+    status: "online",
+    lastSeen: Date.now(),
+    cpu: { current: 12 + generation },
+    memory: { current: 40, total: 8000, used: 3200 },
+    pbs: {
+      instanceId: "pbs-main",
+      version: `3.2.${generation}`,
+      datastores: [],
+    },
+    platformData: { pbs: { instanceId: "pbs-main", hostname: "pbs-main" } },
+  });
+  const state = () => ({
+    resources: [...workloads(), pbs()],
+    connectedInfrastructure: [],
+    activeAlerts: [],
+    recentlyResolved: [],
+    metrics: [],
+    lastUpdate: Date.now(),
+    stats: { version: "6.5.0-test", startTime: new Date().toISOString() },
+  });
+  let socket;
+  await page.routeWebSocket(/\/ws(?:\?|$)/, (ws) => {
+    socket = ws;
+    ws.send(JSON.stringify({ type: "initialState", data: state() }));
+  });
+  await page.route(
+    (url) => url.pathname.startsWith("/api/"),
+    (route) => {
+      const path = new URL(route.request().url()).pathname;
+      if (path === "/api/alerts/active" || path === "/api/orgs")
+        return route.fulfill({ json: [] });
+      if (path === "/api/version")
+        return route.fulfill({
+          json: { version: "6.5.0-test", isDevelopment: true },
+        });
+      if (path === "/api/updates/check")
+        return route.fulfill({
+          json: {
+            available: false,
+            currentVersion: "6.5.0-test",
+            latestVersion: "6.5.0-test",
+          },
+        });
+      if (path === "/api/updates/release-notes")
+        return route.fulfill({
+          json: { version: "6.5.0-test", releaseNotes: "" },
+        });
+      if (path === "/api/security/status")
+        return route.fulfill({
+          json: { hasAuthentication: true, sessionCapabilities: {} },
+        });
+      if (path === "/api/state") return route.fulfill({ json: state() });
+      if (path === "/api/state/summary") return route.fulfill({ json: {} });
+      if (path === "/api/health")
+        return route.fulfill({ json: { status: "healthy" } });
+      if (path === "/api/resources") {
+        const types = new URL(route.request().url()).searchParams
+          .get("type")
+          ?.split(",");
+        const resources = state().resources.filter(
+          (r) => !types || types.includes(r.type),
+        );
+        const query = new URL(route.request().url()).searchParams;
+        const limit = Number(query.get("limit") || 100);
+        const pageNumber = Number(query.get("page") || 1);
+        return route.fulfill({
+          json: {
+            resources: resources.slice(
+              (pageNumber - 1) * limit,
+              pageNumber * limit,
+            ),
+            meta: { totalPages: Math.ceil(resources.length / limit) },
+          },
+        });
+      }
+      if (path === "/api/backups/pve")
+        return route.fulfill({
+          json: {
+            data: {
+              guestSnapshots: workloads().map((w) => ({
+                id: `snap-${w.id}`,
+                name: "pre-upgrade",
+                node: "pve-a",
+                instance: "pve-a",
+                type: "ct",
+                vmid: w.proxmox.vmid,
+                time: new Date().toISOString(),
+                vmstate: false,
+              })),
+              storageBackups: [],
+              backupTasks: [],
+            },
+          },
+        });
+      if (path === "/api/backups/pbs")
+        return route.fulfill({ json: { data: { backups: [] } } });
+      return route.fulfill({ json: { data: [], policy: {} } });
+    },
+  );
+  await page.goto("http://127.0.0.1:5198/proxmox/backups/coverage");
+  await expect(
+    page.getByText("pbs-main-snapshot-0", { exact: true }),
+  ).toBeVisible({ timeout: 60000 });
+  const toggle = page.getByRole("button", {
+    name: /expand details for guest-20-/i,
+  });
+  // The narrow layout exposes this control on keyboard focus, not pointer hover.
+  await toggle.waitFor({ timeout: 60_000 }).catch(async (e) => {
+    console.error(await page.locator("body").innerText());
+    throw e;
+  });
+  await toggle.focus();
+  await toggle.press("Enter").catch(async (error) => {
+    console.error(errors, await page.locator("body").innerText());
+    throw error;
+  });
+  const expanded = page.getByRole("button", {
+    name: /collapse details for guest-20-/i,
+  });
+  await expanded.focus();
+  await expect(
+    page.getByText("Restore evidence", { exact: true }),
+  ).toBeVisible();
+  // Finish layout/scroll synchronisation before measuring refresh effects.
+  await page.waitForTimeout(500);
+  const visibleCoverageRows = await page
+    .locator('[data-proxmox-backup-row="coverage"]')
+    .count();
+  expect(visibleCoverageRows).toBeLessThan(240);
+  expect(visibleCoverageRows).toBeGreaterThan(20);
+  const baseline = await page.evaluate(() => ({
+    y: document.querySelector(".app-scroll-shell").scrollTop,
+    url: location.href,
+  }));
+  expect(baseline.y).toBeGreaterThan(100);
+  const samples = [];
+  for (generation = 1; generation <= 3; generation++) {
+    expect(socket).toBeTruthy();
+    socket.send(JSON.stringify({ type: "rawData", data: state() }));
+    await expect(
+      page
+        .getByText(`guest-20-snapshot-${generation}`, { exact: true })
+        .first(),
+    ).toBeVisible();
+    await expect(
+      page.getByText("Restore evidence", { exact: true }),
+    ).toBeVisible();
+    const sample = await page.evaluate(() => ({
+      y: document.querySelector(".app-scroll-shell").scrollTop,
+      url: location.href,
+    }));
+    console.log(
+      JSON.stringify({
+        generation,
+        ...sample,
+        focused: await expanded.evaluate((el) => el === document.activeElement),
+      }),
+    );
+    await expect(expanded).toBeFocused();
+    expect(sample.url).toBe(baseline.url);
+    expect(Math.abs(sample.y - baseline.y)).toBeLessThanOrEqual(1);
+    samples.push({ generation, ...sample });
+  }
+
+  // Navigate through the real router, then hold a scrolled By date view.
+  await page.getByRole("link", { name: "By date", exact: true }).click();
+  const dateRow = page
+    .locator('[data-proxmox-backup-row="recoverable"]')
+    .filter({ hasText: "guest-20-" })
+    .first();
+  await dateRow.scrollIntoViewIfNeeded();
+  const dateTab = page.getByRole("link", { name: "By date", exact: true });
+  await dateTab.evaluate((el) => el.focus({ preventScroll: true }));
+  const capture = () =>
+    page.evaluate(() => ({
+      y: document.querySelector(".app-scroll-shell").scrollTop,
+      url: location.href,
+      active:
+        document.activeElement?.getAttribute("aria-label") ||
+        document.activeElement?.textContent,
+    }));
+  const dateBaseline = await capture();
+  expect(dateBaseline.y).toBeGreaterThan(100);
+  const dateSamples = [];
+  for (generation = 4; generation <= 6; generation++) {
+    socket.send(JSON.stringify({ type: "rawData", data: state() }));
+    await expect(dateRow).toContainText(`guest-20-snapshot-${generation}`);
+    await expect(dateTab).toBeFocused();
+    const sample = await capture();
+    expect(sample.url).toBe(dateBaseline.url);
+    expect(Math.abs(sample.y - dateBaseline.y)).toBeLessThanOrEqual(1);
+    dateSamples.push(sample);
+  }
+  console.log(
+    JSON.stringify({
+      view: "date",
+      baseline: dateBaseline,
+      samples: dateSamples,
+    }),
+  );
+
+  const pbsToggle = page.getByRole("button", {
+    name: /Expand details for pbs-main-snapshot-/,
+  });
+  await pbsToggle.focus();
+  await pbsToggle.press("Enter");
+  const history = page.getByRole("tab", { name: "History", exact: true });
+  await history.click();
+  await history.focus();
+  await expect(page.getByTestId("resource-metrics-history-tab")).toBeVisible();
+  await page.waitForTimeout(500);
+  const historyBaseline = await capture();
+  const historySamples = [];
+  for (generation = 7; generation <= 9; generation++) {
+    socket.send(JSON.stringify({ type: "rawData", data: state() }));
+    await expect(
+      page
+        .getByText(`pbs-main-snapshot-${generation}`, { exact: true })
+        .first(),
+    ).toBeVisible();
+    await expect(history).toHaveAttribute("aria-selected", "true");
+    await expect(history).toBeFocused();
+    await expect(
+      page.getByTestId("resource-metrics-history-tab"),
+    ).toBeVisible();
+    const sample = await capture();
+    expect(sample.url).toBe(historyBaseline.url);
+    expect(Math.abs(sample.y - historyBaseline.y)).toBeLessThanOrEqual(1);
+    historySamples.push(sample);
+  }
+  console.log(
+    JSON.stringify({
+      view: "PBS History",
+      baseline: historyBaseline,
+      samples: historySamples,
+    }),
+  );
+  expect(errors).toEqual([]);
+  expect(consoleErrors).toEqual([]);
+  console.log(
+    JSON.stringify(
+      {
+        baseline,
+        samples,
+        visibleCoverageRows,
+        pageErrors: errors,
+        consoleErrors,
+      },
+      null,
+      2,
+    ),
+  );
+} finally {
+  await browser?.close();
+  await server.close();
+}