vault: keep systemd-tmpfiles from reaping openbao plugin sockets

go-plugin gives each secrets plugin a control socket at /tmp/pluginNNN.
The daily systemd-tmpfiles-clean deletes /tmp files older than the OS
policy, which severs the socket of a long-lived plugin while its process
keeps running. Every request then fails with rpc Unavailable / dial unix
/tmp/pluginNNN: no such file, until a plugin reload respawns it. This hit
the litellm engine (terraform-vault#112) but the risk is shared by every
OpenBao plugin (gpg, rancher, gitea, ...).

Ship a tmpfiles.d exclude (x /tmp/plugin*) on all vault servers so plugin
sockets survive the cleaner. Takes effect on the next clean, no restart.

Claude-Session: https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT

site/profiles/manifests/vault/server.pp

@@ -122,6 +122,15 @@ class profiles::vault::server (
       ]
     }
 
+    # go-plugin creates each secrets plugin's control socket as /tmp/pluginNNN;
+    # systemd-tmpfiles-clean reaps files aged past the /tmp policy, severing the
+    # socket of a long-lived plugin and orphaning the still-running process
+    # (every request then fails: rpc Unavailable, dial unix /tmp/pluginNNN: no
+    # such file). Exclude the sockets from cleaning for all plugins.
+    systemd::tmpfile { 'openbao-plugin-sockets.conf':
+      content => "x /tmp/plugin*\n",
+    }
+
     # ensure the vault audit log exists
     file { $audit_log:
       ensure => 'file',