Recognize app_super_admin; add-user/add-permission as modal buttons; persist LE key

- app_super_admin is a new cross-app LDAP group (also recognized by
  sso-manager-node and jump-host): added to conf.auth.adminGroups so
  members are always global admins here, same as the existing anti-lockout
  adminUsers/adminGroups mechanism.
- Users and Permissions pages: the always-visible sidebar "Add" forms are
  now an "Add User"/"Add Permission" button in the list header that opens
  an app.modal dialog, matching the hosts.ejs convention.
- The Let's Encrypt ACME account key now defaults to the already-persisted
  /data volume (models/host.js) instead of a CWD-relative path
  (./le_key.cert -> /app/le_key.cert in the container), which was lost on
  every image rebuild. Falls back to the old relative path when /data isn't
  present (e.g. local dev outside docker).

nodejs/models/host.js

@@ -9,10 +9,23 @@ const tldExtract = require('tld-extract').parse_host;
 const LetsEncrypt = require('../utils/letsencrypt');
 const conf = require('@simpleworkjs/conf');
 
+const fs = require('fs');
+const path = require('path');
+
+// Defaults to the same persisted volume Redis uses (/data, see
+// docker-entrypoint.sh's REDIS_DATA_DIR) instead of the old CWD-relative
+// default (./le_key.cert -> /app/le_key.cert), which lives in the
+// container's writable layer and was lost on every rebuild. Falls back to
+// the old relative path when /data isn't present (e.g. local dev outside
+// docker), so it stays writable there too.
+const dataDir = process.env.REDIS_DATA_DIR || '/data';
+const accountKeyPath = fs.existsSync(dataDir) ? path.join(dataDir, 'le_key.cert') : './le_key.cert';
+
 const letsEncrypt = new LetsEncrypt({
 	directoryUrl: conf.environment === "production" ?
 		LetsEncrypt.AcmeClient.directory.letsencrypt.production :
 		LetsEncrypt.AcmeClient.directory.letsencrypt.staging,
+	accountKeyPath,
 });
 
 class Host extends Table{