fix(backup): clarify special core apps restore

Traefik, Samba, Loki core components have special restore behaviors:
it's worth mentioning it.

Author: DavidePrincipi

backup.rst

@@ -144,17 +144,32 @@ To restore an application, at least one backup destination must be
 available.
 
 * Click on the :guilabel:`Restore an app` button.
-* A dialog box will list all applications in the defined backup
+* A dialog box lists all applications found in the configured backup
   destinations. Select the application you want to restore.
 * If the selected application is already installed, a ``Replace existing
-  app`` checkbox becomes visible. If enabled, the existing instance will
-  be removed upon restore.
-* Select an older backup snapshot if the latest one is not preferable.
+  app`` checkbox becomes visible. When enabled, the existing instance will
+  be removed during the restore.
+* Select an older backup snapshot if the latest one is not suitable.
 * Select the target node. Note that in some cases, restoring to certain
   cluster nodes may be restricted due to application policies or node
   resource limitations.
 * Click on the :guilabel:`Restore` button.
 
+Some core applications have special behavior during restore:
+
+- **Traefik** restores only uploaded certificates and user-defined HTTP
+  routes. Refer to :ref:`uploaded-certificates-section` and
+  :ref:`custom-http-route-section`.
+
+- **Loki** restore installs an additional *inactive* Loki instance. It can
+  be used only for log searches, as explained in
+  :ref:`system-logs-section`.
+
+- **Samba** restore behavior depends on whether the AD user domain is
+  already present in the cluster. If present, only shared folder data is
+  restored. If not present, the DC LDAP database is restored as well. See
+  :ref:`file-server-restore` for more information.
+
 
 .. _selective-content-restore:
 

certificates.rst

@@ -152,6 +152,9 @@ key, and chain.
 An application uses the uploaded certificate if it matches its configured
 host name. Wildcard names are supported.
 
+Uploaded certificates are added to Traefik's backup and can be restored
+from it.
+
 .. _certificate-alerts-section:
 
 Receive certificate expiration alerts

log_server.rst

@@ -127,20 +127,30 @@ and best practices, a recommended retention period is 200 days or longer.
 Inactive Loki instances
 -----------------------
 
-When a worker node is promoted to leader, a new Loki instance is installed
-on it and becomes the active instance, while the old instance is marked as
-*inactive*.
+In a NS8 cluster, Loki instances are managed automatically. Only one Loki
+instance is configured as *active* and receives log streams from
+applications. Other instances are *inactive*: they can only be used for
+log searches.
 
-- The new active instance inherits the retention setting from the old one.
+An inactive Loki instance can originate from two situations:
 
-- An inactive instance retains logs based on its last retention setting.
+1. A Loki instance is restored from backup.
+2. When a worker node is promoted to leader, a new Loki instance is
+   installed on the new leader and becomes the active instance, while the
+   previous active instance is marked as *inactive*.
 
-- Log searches can still be performed within an inactive instance.
+In case of a leader promotion, the following also applies:
 
-- Restoring a Loki instance from backup renders it inactive.
+- The new active instance inherits the retention setting of the previous
+  active instance.
 
-- To remove an inactive instance, select the three-dots menu and choose
-  the ``Uninstall`` action.
+- An inactive instance continues to retain logs according to its last
+  retention setting.
+
+As noted, log searches can still be performed on an inactive instance.
+
+To remove an inactive instance, select the three-dots menu and choose the
+``Uninstall`` action.
 
 .. _logs-forwarding-section:
 

proxy.rst

@@ -114,6 +114,9 @@ the following details:
   listing allowed IPv4 addresses or CIDR networks, one per line. By
   default, the route is open to all networks.
 
+Custom HTTP routes are added to Traefik's backup and can be restored from
+it.
+
 .. _lets_encrypt_routes:
 
 Let's Encrypt certificate for HTTP routes