feat(feedback): disclose session sharing in the /feedback acknowledgement

The /feedback acknowledgement now echoes the receiving session id and
reports the mounted telemetry backend's sharing policy: the telemetry seam
exposes a backend-independent TelemetrySharingStatus through a required
abstract sharing member on the Telemetry service, the OTel backend maps its
mode onto it, and the command appends one policy-only sharing sentence
(full / feedback-only / disabled / not configured) to the acknowledgement.
The web client renders the text through the existing command row without a
client change; a new assembled-browser e2e mounts the shipped telemetry row
in FULL mode against a local dead endpoint and pins the shipped default
sentence as a keyless golden.

apps/web/tests/feedback-command.e2e.ts

@@ -0,0 +1,89 @@
+// Keyless assembled-browser coverage for the /feedback command over the
+// shipped Web bundles and the real host wire. The command plane settles
+// without a model turn: the host appends the log-only command/run +
+// feedback/record + command/done lifecycle, and the transcript renders the
+// acknowledgement — the recorded session id plus the session-sharing
+// disclosure — as a persistent command row. The scaffold mounts the shipped
+// telemetry row in FULL mode against a local dead endpoint (no record leaves
+// the process), so the golden pins the shipped default sentence
+// `Session sharing is enabled.`; the per-status sentences are pinned by the
+// package and OTel unit tests.
+import { readFile } 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 {
+  assertFixtureInventory, captureStableAria, compareOrRefreshGolden, fixtureUserPrompts,
+  launchWebScaffold, watchConsole, webSnapshotMode, type WebScaffold,
+} from './scaffold.ts'
+import { connectFreshWorkspace, newEnglishPage, saveFailureShot } from './support.ts'
+
+const SNAPSHOT_DIR = fileURLToPath(new URL('./snapshots/feedback-command', import.meta.url))
+const FIXTURE = join(SNAPSHOT_DIR, 'session.jsonl')
+const ACK_EXPECTED = join(SNAPSHOT_DIR, 'ack.expected.md')
+const MODE = webSnapshotMode()
+// Discard port: loopback listener never binds, so FULL telemetry discloses
+// the shipped default policy without any record reaching a collector.
+const TELEMETRY_URL = 'http://127.0.0.1:9/v1/logs'
+
+const PROMPT = 'Reply with the single word LIGHTHOUSE and stop.'
+
+describe('web e2e: /feedback command acknowledgement', () => {
+  let scaffold: WebScaffold
+  let browser: Browser
+  let page: Page
+  let tripwire: ReturnType<typeof watchConsole>
+
+  beforeAll(async () => {
+    scaffold = await launchWebScaffold({
+      telemetryUrl: TELEMETRY_URL,
+      ...(MODE === 'record' ? {} : { replayFixture: FIXTURE }),
+    })
+    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 })
+    // Fresh world: connecting a workspace births the blank session whose
+    // live composer accepts the slash line.
+    await connectFreshWorkspace(page, scaffold.workspaceCwd)
+  }, 120_000)
+
+  afterAll(async () => {
+    await browser?.close()
+    await scaffold?.close()
+  })
+
+  it('records feedback and renders the acknowledgement with session id and sharing status', async () => {
+    onTestFailed(() => saveFailureShot(page, 'web-e2e-feedback-command'))
+    if (MODE !== 'record') {
+      expect(fixtureUserPrompts(await readFile(FIXTURE, 'utf8'))).toEqual([PROMPT])
+    }
+
+    // First send the recorded prompt so the transcript is active — a command
+    // row does not render while a fresh session is still blank.
+    const input = page.locator('textarea').first()
+    await input.fill(PROMPT)
+    await input.press('Enter')
+    await scaffold.whenTurnSettled()
+    await page.getByText('LIGHTHOUSE', { exact: true }).waitFor({ timeout: 15_000 })
+
+    await input.fill('/feedback the diff view is unreadable')
+    await input.press('Enter')
+    // The command plane settles without a model turn: the ack row names the
+    // recorded session and the mounted FULL backend's disclosure.
+    await page.getByText(/Feedback recorded for session/).waitFor({ timeout: 10_000 })
+    expect(await page.getByText(/Session sharing is enabled/).count()).toBe(1)
+    const snapshot = await captureStableAria(page, '[class*="centerCol"]', scaffold.workspaceCwd)
+    await compareOrRefreshGolden(ACK_EXPECTED, snapshot, MODE)
+
+    expect(tripwire.pageErrors).toEqual([])
+    expect(tripwire.warnings).toEqual([])
+  }, 60_000)
+
+  it.skipIf(MODE === 'record')('keeps the fixture inventory closed', async () => {
+    await assertFixtureInventory(SNAPSHOT_DIR, ['session.jsonl', 'ack.expected.md'])
+  })
+})