fix(web): hide verified cold blank sessions

apps/web/tests/cold-blank-session.e2e.ts

@@ -0,0 +1,60 @@
+/** Cold Session list visibility through the shipped compressed JSONL backend. */
+
+import { mkdir, stat } from 'node:fs/promises'
+import { fileURLToPath } from 'node:url'
+import { join } from 'node:path'
+import type { Browser, Page } from 'playwright'
+import { chromium } from 'playwright'
+import { afterAll, beforeAll, describe, expect, it, onTestFailed } from 'vitest'
+import {
+  captureStableAria, compareOrRefreshGolden, launchWebScaffold, seedBlankSession,
+  watchConsole, webSnapshotMode, type WebScaffold,
+} from './scaffold.ts'
+import { newEnglishPage, saveFailureShot } from './support.ts'
+
+const SNAPSHOT_DIR = fileURLToPath(new URL('./snapshots/cold-blank-session', import.meta.url))
+const SIDEBAR_EXPECTED = join(SNAPSHOT_DIR, 'sidebar.expected.md')
+const MODE = webSnapshotMode()
+const SESSION_ID = 'cold-blank-session-web-e2e'
+const WORKSPACE_NAME = 'cold-blank-workspace'
+
+describe('web e2e: cold blank Session visibility', () => {
+  let scaffold: WebScaffold
+  let browser: Browser
+  let page: Page
+  let tripwire: ReturnType<typeof watchConsole>
+
+  beforeAll(async () => {
+    scaffold = await launchWebScaffold({})
+    const cwd = join(scaffold.workspaceCwd, WORKSPACE_NAME)
+    await mkdir(cwd, { recursive: true })
+    await seedBlankSession(scaffold, SESSION_ID, cwd)
+    const header = (await scaffold.ctx.sessionPersistence.list())
+      .find(candidate => candidate.id === SESSION_ID)
+    if (header === undefined) throw new Error('blank Session fixture did not materialize')
+    const location = scaffold.ctx.sessionPersistence.locate(header)
+    if (location === undefined) throw new Error('JSONL fixture has no physical artifact')
+    expect((await stat(location.path)).size).toBeLessThanOrEqual(1024)
+
+    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 })
+  }, 120_000)
+
+  afterAll(async () => {
+    await browser?.close()
+    await scaffold?.close()
+  })
+
+  it('keeps the verified cold blank Session out of the sidebar', async () => {
+    onTestFailed(() => saveFailureShot(page, 'web-e2e-cold-blank-session'))
+    const tree = page.getByRole('tree', { name: 'Sessions' })
+    await tree.waitFor({ timeout: 30_000 })
+    expect(await tree.getByText(WORKSPACE_NAME, { exact: true }).count()).toBe(0)
+    const sidebar = await captureStableAria(page, '[role="tree"][aria-label="Sessions"]', scaffold.workspaceCwd)
+    await compareOrRefreshGolden(SIDEBAR_EXPECTED, sidebar, MODE)
+    expect(tripwire.pageErrors).toEqual([])
+  })
+})