clanService/wordpress: symlink upgrade-temp-backup and ai1wm-backups to state dir

WordPress writes into wp-content/upgrade-temp-backup (core rollback on
theme/plugin updates) and wp-content/ai1wm-backups (All-in-One WP
Migration). Both sit directly under wp-content, which is the read-only
Nix store path, so creation fails.

Symlink both dirs out to the writable state dir and add matching
tmpfiles rules, same pattern as themes/plugins/upgrade.

Fixes "Could not create the upgrade-temp-backup directory" on Bricks
theme update, and the ai1wm-backups permission errors.

modules/clan/wordpress/default.nix

@@ -83,6 +83,7 @@
                   ln -s "${stateDir hostName}"/wp-content/plugins $out/share/wordpress/wp-content/plugins
                   ln -s "${stateDir hostName}"/wp-content/upgrade $out/share/wordpress/wp-content/upgrade
                   ln -s "${stateDir hostName}"/wp-content/upgrade-temp-backup $out/share/wordpress/wp-content/upgrade-temp-backup
+                  ln -s "${stateDir hostName}"/wp-content/ai1wm-backups $out/share/wordpress/wp-content/ai1wm-backups
 
                 '';
               };
@@ -110,6 +111,8 @@
                 "Z '${stateDir tenant}/wp-content/upgrade' 0750 ${user} ${webserver.group} - -"
                 "d '${stateDir tenant}/wp-content/upgrade-temp-backup' 0750 ${user} ${webserver.group} - -"
                 "Z '${stateDir tenant}/wp-content/upgrade-temp-backup' 0750 ${user} ${webserver.group} - -"
+                "d '${stateDir tenant}/wp-content/ai1wm-backups' 0750 ${user} ${webserver.group} - -"
+                "Z '${stateDir tenant}/wp-content/ai1wm-backups' 0750 ${user} ${webserver.group} - -"
               ]) settings.tenants
             );