fix(admin): explicit role-change button label

The user-management role-change button rendered a bare arrow
followed by "User" / "Admin" — direction was ambiguous
("does the arrow mean 'now they are User' or 'send them down
to User'?") and the label carried no aria-label. Replaced the
arrow text with explicit "Make user" / "Make admin"
("Zum Benutzer" / "Zum Admin"), and added the same string as
aria-label so screen readers announce the action verb instead
of the visible-only arrow glyph.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

messages/de.json

@@ -1682,8 +1682,8 @@
     "editUserTitle": "Benutzer bearbeiten: {name}",
     "demoteToUser": "Zu User degradieren",
     "promoteToAdmin": "Zum Admin befördern",
-    "toUser": "→ User",
-    "toAdmin": "→ Admin",
+    "toUser": "Zum Benutzer",
+    "toAdmin": "Zum Admin",
     "ownRoleUnchangeable": "Eigene Rolle nicht änderbar",
     "lastAdminError": "Der letzte Admin kann nicht degradiert werden",
     "resetPassword": "Passwort zurücksetzen",

messages/en.json

@@ -1682,8 +1682,8 @@
     "editUserTitle": "Edit user: {name}",
     "demoteToUser": "Demote to user",
     "promoteToAdmin": "Promote to admin",
-    "toUser": "→ User",
-    "toAdmin": "→ Admin",
+    "toUser": "Make user",
+    "toAdmin": "Make admin",
     "ownRoleUnchangeable": "Cannot change own role",
     "lastAdminError": "Cannot demote the last admin",
     "resetPassword": "Reset password",

src/components/admin/user-management-section.tsx

@@ -182,6 +182,11 @@ export function UserManagementSection() {
               ? t("admin.demoteToUser")
               : t("admin.promoteToAdmin")
         }
+        aria-label={
+          u.role === "ADMIN"
+            ? t("admin.demoteToUser")
+            : t("admin.promoteToAdmin")
+        }
       >
         <Shield className="mr-1 h-3 w-3" aria-hidden="true" />
         {u.role === "ADMIN" ? t("admin.toUser") : t("admin.toAdmin")}