Admin PIN: the fields say enough

The paragraph under the PIN fields explained what the PIN covers and how to
clear it by hand — and only someone already past the PIN could read it, so
the recovery note was never where it was needed. Gone, with the dead style
and the element lookup that hung off it.

The live line under the heading stays: it is the only thing that says
whether admin is locked, and the only warning that a passcode in the
server's environment outranks whatever is set here.

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

public/admin/admin.js

@@ -132,7 +132,6 @@ function renderPin(state) {
     : set
       ? 'Admin is locked. This page asks for the PIN, and so does every admin request.'
       : 'Admin is open to anyone on the network. Set a 6-digit PIN to lock it.';
-  if (state.dataDir) document.getElementById('pin-file').textContent = state.dataDir + '/proddash.json';
 }
 
 function pinMessage(text, bad = false) {