diff --git a/apps/web/tests/startup-auto-selection.e2e.ts b/apps/web/tests/startup-auto-selection.e2e.ts
new file mode 100644
index 0000000000..6ffb6cbf83
--- /dev/null
+++ b/apps/web/tests/startup-auto-selection.e2e.ts
@@ -0,0 +1,119 @@
+// Web e2e scenario: startup auto-selection keeps the hero on screen.
+//
+// A page load with a workspace already registered runs
+// `WorkspacesService.startInitialSelection`: it connects the most recent
+// workspace and opens its blank session. `openState` flips to `loading` the
+// moment `open()` lands, which used to drive `data-phase=settling` on the
+// conversation root — `visibility:hidden` over the composer seat and the
+// header for the whole `session.history` round-trip, so the center column went
+// blank and repainted, reading as a full-page refresh on every launch.
+//
+// The unit spec pins the phase condition over hand-built stores. What only the
+// assembled application can show is that the path a user actually takes
+// reaches it: the real selection service, the real client session opening over
+// the real /api transport, and a real browser deciding what is painted.
+//
+// The round-trip against a loopback host is far too fast to observe, so this
+// scenario HOLDS the `session.history` response open at the browser's network
+// boundary and asserts the visible frame while it is in flight. That gate is
+// what makes the assertions non-vacuous: with the exemption reverted the held
+// window is exactly when `settling` is painted and the composer is hidden.
+//
+// Zero model calls: registering a workspace and opening its blank session are
+// host RPCs with no model involvement. A stray stream would fail loud with
+// NO_ADAPTER.
+import type { Browser, Page } from 'playwright'
+import { chromium } from 'playwright'
+import { afterAll, beforeAll, describe, expect, it, onTestFailed } from 'vitest'
+import { acknowledgeReloadConnectionLoss, launchWebScaffold, watchConsole, type WebScaffold } from './scaffold.ts'
+import { connectFreshWorkspace, newEnglishPage, saveFailureShot } from './support.ts'
+
+/** Wire path of the history round-trip the conversation root waits out (POST /api/session.history). */
+const HISTORY_ROUTE = '**/api/session.history'
+
+/**
+ * The conversation root's own phase attribute. `div` disambiguates it from the
+ * composer textarea, which carries an unrelated `data-phase` of its own.
+ */
+const ROOT_PHASE = 'div[data-phase]'
+
+/** Every distinct `data-phase` the conversation root shows, in order, across one page load. */
+function recordedPhases(page: Page): Promise<string[]> {
+  return page.evaluate(() => (window as unknown as { __conversationPhases: string[] }).__conversationPhases)
+}
+
+describe('web e2e: startup auto-selection', () => {
+  let scaffold: WebScaffold
+  let browser: Browser
+  let page: Page
+  let tripwire: ReturnType<typeof watchConsole>
+
+  beforeAll(async () => {
+    scaffold = await launchWebScaffold({})
+    browser = await chromium.launch()
+    page = await newEnglishPage(browser)
+    tripwire = watchConsole(page)
+    await page.goto(scaffold.baseUrl, { waitUntil: 'load' })
+    await page.waitForSelector('[class*="frame"]', { timeout: 30_000 })
+    // A registered workspace is the precondition for auto-selection: the first
+    // load has nothing to select, so the reload below is the path under test.
+    await connectFreshWorkspace(page, 'startup-auto-selection')
+  }, 180_000)
+
+  afterAll(async () => {
+    await browser?.close()
+    await scaffold?.close()
+  })
+
+  it('keeps the hero and the composer on screen while the auto-selected blank session opens', async () => {
+    onTestFailed(() => saveFailureShot(page, 'web-e2e-startup-auto-selection'))
+    // Runs before any page script on the reload below, so the first phase the
+    // root ever renders is recorded, not just the ones after a listener attaches.
+    await page.addInitScript(() => {
+      const phases: string[] = []
+      ;(window as unknown as { __conversationPhases: string[] }).__conversationPhases = phases
+      setInterval(() => {
+        const phase = document.querySelector('div[data-phase]')?.getAttribute('data-phase')
+        if (phase === null || phase === undefined) return
+        if (phases[phases.length - 1] !== phase) phases.push(phase)
+      }, 8)
+    })
+
+    let releaseHistory = (): void => {}
+    const historyHeld = new Promise<void>((resolve) => { releaseHistory = resolve })
+    let historyRequested = (): void => {}
+    const historyInFlight = new Promise<void>((resolve) => { historyRequested = resolve })
+    let gated = false
+    await page.route(HISTORY_ROUTE, async (route) => {
+      // Only the auto-selection's own round-trip is held; later pages must not
+      // deadlock behind a gate this test has already released.
+      if (gated) { await route.continue(); return }
+      gated = true
+      historyRequested()
+      await historyHeld
+      await route.continue()
+    })
+
+    const warningsBefore = tripwire.warnings.length
+    await page.reload({ waitUntil: 'commit' })
+    await historyInFlight
+
+    // The frame a user sees while the session is still opening: hero phase, the
+    // hero title, and a composer that is actually painted (`settling` hides the
+    // seat with `visibility:hidden`, which Playwright reports as not visible).
+    await page.waitForSelector(ROOT_PHASE, { timeout: 15_000 })
+    expect(await page.locator(ROOT_PHASE).first().getAttribute('data-phase')).toBe('hero')
+    expect(await page.getByText("Let's start building").isVisible()).toBe(true)
+    expect(await page.locator('textarea').first().isVisible()).toBe(true)
+
+    releaseHistory()
+    await page.locator('textarea:enabled[placeholder="Describe what you want to build"]')
+      .waitFor({ timeout: 15_000 })
+    acknowledgeReloadConnectionLoss(tripwire, warningsBefore)
+
+    // Settling is not merely absent from the frame sampled above: the root
+    // never entered it at any point of the load.
+    expect(await recordedPhases(page)).toEqual(['hero'])
+    expect(tripwire.pageErrors).toEqual([])
+  }, 120_000)
+})
diff --git a/apps/web/tsconfig.json b/apps/web/tsconfig.json
index a4cd2d9121..7e4e278f3a 100644
--- a/apps/web/tsconfig.json
+++ b/apps/web/tsconfig.json
@@ -47,7 +47,8 @@
     "tests/queue-actions.e2e.ts",
     "tests/skill-invocation-policy.e2e.ts",
     "tests/permission-policy-context.e2e.ts",
-    "tests/access-confirmation.e2e.ts"
+    "tests/access-confirmation.e2e.ts",
+    "tests/startup-auto-selection.e2e.ts"
   ],
   "references": [
     {
diff --git a/tsconfig.host.json b/tsconfig.host.json
index 0b2a16c7f8..f474693e7c 100644
--- a/tsconfig.host.json
+++ b/tsconfig.host.json
@@ -35,6 +35,7 @@
     "apps/web/tests/skill-invocation-policy.e2e.ts",
     "apps/web/tests/permission-policy-context.e2e.ts",
     "apps/web/tests/access-confirmation.e2e.ts",
+    "apps/web/tests/startup-auto-selection.e2e.ts",
     "apps/cli/tests/**/*.ts",
     "examples/*/src/**/*.ts",
     "examples/*/start.ts",