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.

src/content/partials/service-hostnames.mdx

@@ -1,12 +1,11 @@
 Some applications need to connect to databases or caches. Use these hostnames from inside your site — they only resolve within your hosting container, so they don't work from your laptop.
 
-| Service     | Hostname    | Default port | Notes                                                  |
-| ----------- | ----------- | ------------ | ------------------------------------------------------ |
-| MySQL       | `mysql`     | 3306         | Username, password, and database from your WHP panel.  |
-| PostgreSQL  | `postgres`  | 5432         | Available on most plans; ask support if it's missing.  |
-| Memcached   | `memcache`  | 11211        | No auth; isolated per container.                       |
-| Redis       | `redis`     | 6379         | Single DB per site; password in panel.                 |
+| Service     | Hostname    | Default port | Notes                                                                            |
+| ----------- | ----------- | ------------ | -------------------------------------------------------------------------------- |
+| MySQL       | `mysql`     | 3306         | Username, password, and database from the **MySQL Management** page.             |
+| PostgreSQL  | `postgres`  | 5432         | Username, password, and database from the **PostgreSQL** page.                   |
+| Valkey      | `valkey`    | 6379         | Redis wire-compatible (phpredis, Predis, ioredis work unchanged). No password — the connection is network-isolated to your account. Enable on the **Valkey Cache** page first. |
 
-For **email** (IMAP, POP3, SMTP), the mail server hostname is **per-domain** — check the **Dashboard** page in WHP for the exact hostname to use in your email client or app.
+For **email**, the mail server hostname is a per-server value (e.g. `mail01.cloud-hosting.io`) and is shown on the **Dashboard** page under Server Information.
 
 **Connecting from your laptop?** Use the panel's **phpMyAdmin** (MySQL) or **Adminer** (PostgreSQL) for ad-hoc queries — direct external connections to these internal services are not exposed for security reasons.