docs(whp): add how-to articles (domain, site, email, backups) + placeholder screenshots

Placeholders are 1440x900 'Screenshot pending' PNGs that will be
overwritten by real captures via 'npm run screenshots' once a demo
user is provisioned.

src/content/docs/whp/how-to/backups.mdx

@@ -0,0 +1,90 @@
+---
+title: Backups
+description: Confirm WHP is backing up your site, restore individual files, and download archives.
+sidebar:
+  order: 4
+---
+
+import { Steps, Aside } from '@astrojs/starlight/components';
+import SignIn from '~/content/partials/signing-in.mdx';
+import Support from '~/content/partials/support-link.mdx';
+
+WHP runs **automatic daily backups** of your site files and databases. You don't have to set anything up for this to happen — but it's worth knowing how to confirm a backup ran, restore something, and download an archive when you need to.
+
+## What's backed up by default
+
+- **Site files** — everything under each domain folder.
+- **Databases** — all MySQL databases attached to your account.
+- **Email** — mailboxes and their contents (depending on your plan).
+
+Retention is shown on your plan page. The default tier keeps **7 daily backups**.
+
+## Sign in to WHP
+
+<SignIn />
+
+## Configure your backup schedule
+
+<Steps>
+
+1. From the sidebar, open **Backups → Settings**.
+   ![WHP Backup Settings page](~/assets/screenshots/whp/whp-backups-settings.png)
+
+2. Confirm the **schedule** (default: daily, overnight). Adjust if your plan permits.
+
+3. (Optional) Enable **off-server backups** to a separate storage location — recommended for anything you can't afford to lose.
+
+</Steps>
+
+## Verify a backup actually ran
+
+<Steps>
+
+1. Open **Backups → History**.
+   ![WHP Backup History page](~/assets/screenshots/whp/whp-backups-history.png)
+
+2. Confirm the most recent entry is from **within the last 24 hours** and shows **Success**.
+
+3. Click the entry to see what was included — files, databases, email — and the total size.
+
+</Steps>
+
+<Aside type="tip">
+  Add a calendar reminder to check this monthly. Backups that fail silently are the worst kind.
+</Aside>
+
+## Test a restore (recommended quarterly)
+
+The best time to discover your backup isn't working is *not* when you actually need it. Test surgically:
+
+1. In **History**, click a recent backup → **Restore preview**.
+2. Pick a single file — your site's `index.php`, for example — and restore just that one file.
+3. Confirm it appears correctly. If yes, the restore pipeline works.
+
+Don't do a full restore unless you genuinely need to — it rewrites your live site.
+
+## Download a backup
+
+To grab a copy off-server:
+
+1. From **History**, click a backup → **Download**.
+2. WHP packages it as `.tar.gz` and offers a one-time download link that's valid for 24 hours.
+
+## Troubleshooting
+
+**Backup failed.** Click the failed row to see the error. Common causes:
+
+- Disk full or close to it — check **Overview → Resource usage** and consider a [resource upgrade](/whp/add-ons/resource-upgrades/).
+- A very large mailbox slowed the run — consider the [archival email add-on](/whp/add-ons/archival-email/) to relieve mailbox pressure.
+- Transient lock or maintenance window — let it retry overnight before opening a ticket.
+
+**Restore "succeeded" but my file isn't there.** Check the **path** shown on the backup's detail page — your restore landed where the backup says it would, which may not match your current site layout if you've moved files around.
+
+## Related
+
+- [Archival email add-on](/whp/add-ons/archival-email/)
+- [Resource upgrades](/whp/add-ons/resource-upgrades/)
+
+## Still stuck?
+
+<Support />