Add how-to page for the new SFTP SSH key management feature

Documents the customer-facing SFTP SSH Keys page shipped in WHP 2026.09.11
(sidebar: Security → SFTP SSH Keys) — adding/removing SSH public keys that
authorize SFTP login alongside the account password, useful for teams
sharing one hosting account without sharing a password. Walked the live
page as the demo customer account and captured real redacted screenshots
(empty state, filled Add Key form, populated key list). Also documents a
non-obvious live-verified detail: the visible Comment column reflects the
key's own comment (ssh-keygen -C), not the separate Note field, which only
goes to the audit log. Cross-linked from Create a site.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/content/docs/whp/how-to/create-a-site.mdx

@@ -56,6 +56,8 @@ When you connect via SFTP, your account home (`/docker/users/<your-user>/`) show
 
 Upload your files to the right place and the site picks them up immediately.
 
+Logging in with your account password works out of the box. If you'd rather use an SSH key instead — or need to let a teammate connect without sharing your password — see [Manage SFTP SSH keys](/whp/how-to/manage-sftp-ssh-keys/).
+
 ## Connect to databases and caches
 
 <Hostnames />
@@ -82,6 +84,7 @@ Open your domain in a browser. You should see your site, or the default "no cont
 
 - [Add a domain](/whp/how-to/add-a-domain/)
 - [Service hostnames](/whp/reference/service-hostnames/)
+- [Manage SFTP SSH keys](/whp/how-to/manage-sftp-ssh-keys/)
 
 ## Still stuck?
 

src/content/docs/whp/how-to/manage-sftp-ssh-keys.mdx

@@ -0,0 +1,111 @@
+---
+title: Manage SFTP SSH keys
+description: Add SSH public keys to your account so you — and anyone else on your team — can log in over SFTP without sharing a password.
+sidebar:
+  order: 8
+---
+
+import { Steps, Aside } from '@astrojs/starlight/components';
+import SignIn from '~/content/partials/signing-in.mdx';
+import Support from '~/content/partials/support-link.mdx';
+
+SFTP normally logs in with your account password. SSH keys give you (or a teammate) a second way in — no password typing, and no need to share your password with anyone. Add one key per person, and remove any key on its own without touching anyone else's.
+
+## Before you start
+
+- An SSH key pair. If you don't have one yet, the steps below cover generating one — it takes about a minute.
+- About 5 minutes.
+
+<Aside type="tip">
+  The main reason to use this: if more than one person needs SFTP access to the same hosting account, everyone can add their own key instead of all sharing one password. Removing someone's access later is just removing their key.
+</Aside>
+
+## Sign in to WHP
+
+<SignIn />
+
+## Steps
+
+<Steps>
+
+1. In the sidebar, click **Security → SFTP SSH Keys**.
+   ![WHP SFTP SSH Keys page with no keys added yet](~/assets/screenshots/whp/whp-sftp-keys-empty.png)
+
+2. If you don't already have an SSH key, generate one on your own machine:
+
+   ```bash
+   ssh-keygen -t ed25519 -C "your-email-or-a-note-to-yourself"
+   ```
+
+   Accept the default file location (`~/.ssh/id_ed25519`) and set a passphrase if you'd like one. If you already have a key, you'll find it at `~/.ssh/id_ed25519.pub` (or `~/.ssh/id_rsa.pub` for an older RSA key).
+
+   <Aside type="caution">
+     Only ever paste the **`.pub`** file's contents — that's the *public* key, safe to share. Never paste the file without `.pub` (or one that starts with `-----BEGIN OPENSSH PRIVATE KEY-----`) anywhere. The panel will refuse anything that looks like a private key, but it's worth knowing the difference.
+   </Aside>
+
+3. Copy the full contents of the `.pub` file — one line, starting with the key type (`ssh-ed25519`, `ssh-rsa`, etc.).
+
+4. Paste it into the **Public key** box in the **Add Key** card. The **Note** field is optional — whatever you type there is recorded in the account's audit log, but it isn't what shows in the key list below (see the tip after this list for how to label a key so you can actually tell it apart later).
+   ![Add Key form filled in with a public key and a note](~/assets/screenshots/whp/whp-sftp-keys-add-form.png)
+
+5. Click **Add Key**. It appears in the **Authorized Keys** table immediately and works right away — no separate activation step.
+   ![Authorized Keys table showing one added key](~/assets/screenshots/whp/whp-sftp-keys-list.png)
+
+</Steps>
+
+<Aside type="tip">
+  The **Comment** column in the table comes from the key itself, not from the Note field — it's whatever followed the key type when the key was generated (the `-C "..."` value above, e.g. `your-email-or-a-note-to-yourself`). If several people are adding keys to the same account, agree on a naming convention for `-C` (e.g. `-C "dana-laptop"`) so everyone can tell the keys apart at a glance. A key generated without `-C` shows as **(no comment)**.
+</Aside>
+
+## Connect over SFTP with your key
+
+Point your SFTP client at the private key file (the one *without* `.pub`):
+
+```bash
+sftp -i ~/.ssh/id_ed25519 <username>@<your-server>.cloud-hosting.io
+```
+
+Replace `<username>` with your WHP username and `<your-server>` with your server's hostname (find it on the **Dashboard** page under Server Information). Graphical clients — FileZilla, Cyberduck, WinSCP — all support key-based login too: point the client's "private key" field at `~/.ssh/id_ed25519` instead of filling in a password.
+
+Your account password still works for SFTP exactly as before. Adding a key doesn't disable it.
+
+## Supported key types
+
+- **`ssh-ed25519`** — recommended. Generate with `ssh-keygen -t ed25519`.
+- `ecdsa-sha2-nistp256`, `ecdsa-sha2-nistp384`, `ecdsa-sha2-nistp521`
+- `ssh-rsa`
+- `sk-ssh-ed25519@openssh.com`, `sk-ecdsa-sha2-nistp256@openssh.com` — for a FIDO/hardware security key (e.g. a YubiKey)
+
+If a key is malformed, an unsupported type, or technically well-formed but not something the SFTP server can actually use, the panel rejects it with an explanation instead of adding it — so a key that's been accepted is a key that works.
+
+## Remove a key
+
+Find the key in the **Authorized Keys** table and click **Remove**. Confirm in the dialog — the fingerprint and comment are shown so you can be sure you're removing the right one. This takes effect immediately: anyone using that key loses SFTP access right away, but password login is unaffected.
+
+There's no restriction on removing your last key. If you remove every key on the account, SFTP still works with your account password — keys are additive, not a replacement for it.
+
+Common reasons to remove a key: someone leaves the team, or a laptop with a key on it is lost or retired.
+
+<Aside type="note">
+  Keys can also be added or removed directly in `~/.ssh/authorized_keys` over SFTP itself, and valid changes made that way show up here too. But changes made outside this page aren't recorded in the audit log, and anything in that file the panel doesn't recognize (an unsupported key type, a malformed line, a restricted `command=`/`from=` entry) is cleaned up automatically the next time this page loads. Comments and blank lines are always left alone.
+</Aside>
+
+## If you manage this account on someone else's behalf
+
+Root and support staff reach the same page for any customer account — either from the same **Security → SFTP SSH Keys** sidebar entry (which then shows an account selector), or via a **SFTP Keys** button on that customer's row on the **User Management** page. Everything above works the same way once an account is selected; the only difference is picking whose keys you're managing first.
+
+## Troubleshooting
+
+**"This key is already present."** That exact key (by fingerprint) is already on the account — check the table before adding it again.
+
+**Key added, but SFTP still asks for a password.** Double-check you're pointing your client at the matching **private** key file (no `.pub`), and that the username in your connection matches the account the key was added to.
+
+**A key I added over raw SFTP disappeared.** If it didn't meet this page's rules (unsupported type, malformed, or carried a restricted option), it was removed the next time the page loaded — add it here instead so it's validated and recorded properly.
+
+## Related
+
+- [Create a site](/whp/how-to/create-a-site/) — including where your files go over SFTP.
+
+## Still stuck?
+
+<Support />