feat: Implement admin-only specialties management interface

- Added MailerAttachmentPolicy for validating email attachments against server rules.
- Introduced fis.specialties.js for managing hidden maintenance actions via an admin interface.
- Created fis.specialties.scss for styling the specialties management UI.
- Added German localization for specialties management in fis.specialties_txt_de.js.
- Developed CSS for specialties management in fis.specialties.css.
- Implemented server-side stored procedure fds__admin_backupAndClearInvoiceFile for backing up and clearing invoice files.
- Created fds__invoice_file_backups table to store backup records of invoice files.

Fuchs/js/intranet/fis_main_menu.js

@@ -12,21 +12,23 @@
 })();
 
 /* "Administration" is a single sidemenu dropdown (ocmsmenu supports nested items via `itm`)
-   containing three buttons — Benutzerverwaltung (fn=usr), Gruppenverwaltung (fn=usrgrp) and
-   Systemüberwachung (fn=admin) — all restricted to users whose fds_sys authorization exceeds 4.
-   One auth check gates the whole dropdown; it (and therefore all module scripts) is only added
-   after that check resolves, so lower-privileged users never see it or fetch any module's code.
-   Called from fis_main_go.js once the DOM (and the initial main menu) is ready. */
+   containing four buttons — Benutzerverwaltung (fn=usr), Gruppenverwaltung (fn=usrgrp),
+   Systemüberwachung (fn=admin) and Spezialfunktionen (fn=specialties) — all restricted to users
+   whose fds_sys authorization exceeds 4. One auth check gates the whole dropdown; it (and
+   therefore all module scripts) is only added after that check resolves, so lower-privileged
+   users never see it or fetch any module's code. Called from fis_main_go.js once the DOM (and
+   the initial main menu) is ready. Returns a promise that settles once the menu is final. */
 $fis.addAdminMenuButtonsIfAuthorized = function () {
-    if ($('#m_admin_grp').length > 0) { return; }   // idempotent
-    $fis.getAuth('fds_sys').then(function (auth) {
+    if ($('#m_admin_grp').length > 0) { return Promise.resolve(); }   // idempotent
+    return $fis.getAuth('fds_sys').then(function (auth) {
         if ((auth || -1) > 4 && $('#m_admin_grp').length === 0) {
             $ocms.ocmsmenu.push({
                 lbl: $t.m_admin, id: 'm_admin_grp', ico: 'glyphicon glyphicon-cog',
                 itm: [
                     { lbl: $t.m_usr, id: 'm_usr', fnc: 'init:usr', ico: 'glyphicon glyphicon-user' },
                     { lbl: $t.m_usrgrp, id: 'm_usrgrp', fnc: 'init:usrgrp', ico: 'glyphicon glyphicon-list' },
-                    { lbl: $t.m_admin_status, id: 'm_admin', fnc: 'init:admin', ico: 'glyphicon glyphicon-dashboard' }
+                    { lbl: $t.m_admin_status, id: 'm_admin', fnc: 'init:admin', ico: 'glyphicon glyphicon-dashboard' },
+                    { lbl: $t.m_specialties, id: 'm_specialties', fnc: 'init:specialties', ico: 'glyphicon glyphicon-wrench' }
                 ]
             });
             /* Re-render the main menu cleanly: drop the previously generated menu list
@@ -35,4 +37,23 @@ $fis.addAdminMenuButtonsIfAuthorized = function () {
             $('#mainmenu').ocmsmenu($ocms.ocmsmenu);
         }
     }).catch(function () { /* auth lookup failed → leave the menu unchanged */ });
+};
+
+/* Deep link: the server renders the same SPA shell for every /{fn} URL (IntranetController.Index
+   ignores fn), so opening e.g. /specialties directly would otherwise just show the dashboard.
+   Opens the module named by the first path segment — but only one the user's menu actually
+   offers (`init:<fn>` item, incl. the admin dropdown), so arbitrary paths, /do/… links and
+   pre-auth flows never trigger a module load. Must run after the admin menu settled. */
+$fis.openModuleFromPath = function () {
+    let fn = (window.location.pathname.split('/')[1] || '').toLowerCase();
+    if (!/^[a-z]+$/.test(fn) || fn === 'home') { return; }
+    let offered = false;
+    let scan = function (items) {
+        $.each(items || [], function (i, it) {
+            if (it.fnc === 'init:' + fn) { offered = true; }
+            if (it.itm) { scan(it.itm); }
+        });
+    };
+    scan($ocms.ocmsmenu);
+    if (offered) { $ocms.init(fn); }
 };