docs: verify against real WHP + capture real screenshots

Discovery against the demo account on whp01 surfaced several inaccuracies:

- Cache is Valkey (Redis wire-compatible), not Redis or Memcached.
  No Memcached is offered as a separate service.
- Site Monitoring is the sidebar label (not 'AI Monitor').
- 'Add a domain' has no Primary/Add-on distinction.
- Sites form: 'Container Type' (not 'Site type'), Number of Containers
  (1-10 for horizontal scaling), CPU per Container (default 0.25),
  Memory per Container (default 256MB), SSL inline on the same form.
- Backups: default retention 5 days / 10 backups; on-demand + scheduled;
  S3 backup targets are visible and configurable.
- Email: per-domain settings live behind 'Setup Instructions' on the
  Email page; mail server hostname is on the Dashboard (per-server,
  e.g. mail01.cloud-hosting.io), not per-domain.

Also reworked the screenshot pipeline:
- New shots.config.ts targets the real index.php?page=... URLs
- Added redactSensitive() step that runs before each screenshot to swap
  server names, IPs, mail hostnames, and demo-user-isms with neutral
  placeholders. This keeps docs portable across the fleet.
- Hides .brand-full and .navbar-text (top-bar server identifier and
  Welcome greeting).
- Captured 9 real WHP screenshots; removed stale placeholders.

tools/screenshots/peek.ts

@@ -0,0 +1,53 @@
+/**
+ * One-shot peek script: log in, navigate to a specific URL, screenshot it.
+ * Usage: PEEK_URL=... npx tsx tools/screenshots/peek.ts
+ */
+import { chromium, type Page } from 'playwright';
+import { mkdir } from 'node:fs/promises';
+import { resolve, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const OUT_DIR = resolve(__dirname, '../../src/assets/screenshots/whp');
+
+function need(name: string): string {
+  const v = process.env[name];
+  if (!v) throw new Error(`missing env: ${name}`);
+  return v;
+}
+
+const BASE = need('WHP_BASE');
+const USER = need('WHP_USER');
+const PASS = need('WHP_PASS');
+const PEEK = need('PEEK_URL');
+const ID = process.env.PEEK_ID ?? '_peek';
+
+async function login(page: Page): Promise<void> {
+  await page.goto(`${BASE}/login.php`, { waitUntil: 'domcontentloaded' });
+  await page.fill('input[name="user"]', USER);
+  await page.fill('input[name="password"]', PASS);
+  await page.click('button[type="submit"]');
+  await page.waitForLoadState('networkidle');
+}
+
+async function main(): Promise<void> {
+  const browser = await chromium.launch({ headless: true });
+  const ctx = await browser.newContext({ ignoreHTTPSErrors: true, viewport: { width: 1440, height: 900 } });
+  const page = await ctx.newPage();
+  try {
+    await login(page);
+    await page.goto(`${BASE}${PEEK}`);
+    await page.waitForLoadState('networkidle');
+    await mkdir(OUT_DIR, { recursive: true });
+    const out = resolve(OUT_DIR, `${ID}.png`);
+    await page.screenshot({ path: out, fullPage: true });
+    console.log(`captured ${PEEK} -> ${out}`);
+  } finally {
+    await browser.close();
+  }
+}
+
+main().catch((err) => {
+  console.error(err);
+  process.exit(1);
+});