Split Admin module into Status and User Management under one sidemenu dropdown

Splits fn=admin into two independent modules: the original status
dashboard stays at fn=admin, user management moves to a new fn=usr
(IntranetController.AdminUsers.cs, fis.usr.js). Both are now reached
through a single "Administration" sidemenu dropdown (Systemüberwachung /
Benutzerverwaltung) gated by one shared fds_sys > 4 check, per ADR 0015
(supersedes 0014's "fold into one module" choice).

Also fixes the password-reset validation to check only a plain 6-char
minimum instead of silently also requiring ValidatePassword's default
2-uppercase/2-lowercase/2-digit composition, which contradicted the
"mind. 6 Zeichen" message shown to the admin.

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

Fuchs/bdlconfig.json

@@ -170,5 +170,24 @@
       "js/intranet/modules/fis.admin.scss"
     ],
     "minify": { "enabled": true }
+  },
+  {
+    "context": "intranet:usr",
+    "outputFileName": "wwwroot/web/fis.usr.de.js",
+    "inputFiles": [
+      "js/intranet/modules/fis.usr_txt_de.js",
+      "js/intranet/modules/fis.usr.js"
+    ],
+    "minify": { "enabled": true }
+  },
+  {
+    "context": "intranet:usr",
+    "outputFileName": "wwwroot/web/fis.usr.min.css",
+    "inputFiles": [
+      "css/intranet/oci_variables.scss",
+      "css/intranet/fis_variables.scss",
+      "js/intranet/modules/fis.usr.scss"
+    ],
+    "minify": { "enabled": true }
   }
 ]