docs(admin): address remaining review feedback

- Drop "first...per PHP request" phrasing — only one PROPFIND per PHP
  request, so the qualifier was false; simplify to "on each PROPFIND request"
- Fix renames-section reference: "option A" is SMB notify, not "Once per
  direct access"; use the mount option name directly instead
- Restore AIO note for files_external:scan (removed in previous commit
  but reviewer wants it kept, using updated command)

Signed-off-by: skjnldsv <skjnldsv@protonmail.com>

Author: skjnldsv

admin_manual/configuration_files/external_storage_configuration_gui.rst

@@ -105,7 +105,7 @@ individually with the following options:
 * Enable Sharing
 * **Filesystem check frequency** — controls how the server rescans an external
   storage path when a WebDAV ``PROPFIND`` request arrives for it.
-  **Once per direct access** rescans on the first ``PROPFIND`` per PHP request;
+  **Once per direct access** rescans on each ``PROPFIND`` request;
   **Never** skips the rescan entirely. This setting does *not* cause Nextcloud
   or desktop clients to poll automatically. See
   :ref:`external_storage_change_detection_label` for details.
@@ -238,11 +238,18 @@ rescans the external storage periodically using its mount ID:
 See :doc:`../occ_command` for the full ``files_external:scan`` reference. A typical
 interval is every 15 minutes; adjust to balance freshness against server load.
 
+.. note::
+   If you are running Nextcloud AIO, the equivalent command is:
+
+   .. code-block:: console
+
+      sudo docker exec --user www-data -it nextcloud-aio-nextcloud php occ files_external:scan <mount_id>
+
 Limitation: renames are not detected reliably
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Whenever Nextcloud rescans an external storage — whether via periodic cron
-(option B) or on direct access (option A setting **Once per direct access**) —
+(option B) or via the **Once per direct access** filesystem check frequency setting —
 the scanner cannot reliably detect that an entry was **renamed**. It sees the old
 name as deleted and the new name as a newly created entry. This causes
 **metadata loss**: all shares, tags, comments, and activity history associated