Add admin user management and password-change flow

Introduce full admin user listing/detail endpoints and a forced password-change flow. Backend: make CurrentUserResponse.UserName nullable and add ToCurrentUserResponseAsync extension; AppUserController now exposes GET /auth/user (list) and GET /auth/user/{id} (detail) using UserManager and Admin-only policy; AuthController uses the new mapper and after successful password change clears MustChangePassword, updates UpdatedAt and persists changes (with error handling) before updating security stamp. Frontend: add admin users pages (list + detail), ChangePassword page and route, adminUsers and enhanced authSession services (typed responses, changePassword API, error mapping), router guard to redirect users with mustChangePassword=true to the change-password flow, and show success banner on login after password change. UI tweaks: separate admin section in sidebar, add password-change entries in account menu, footer sizing fixes, and various layout/UX improvements. These changes enable admin account management and enforce secure password updates across the app.

GUI/src/Layout.vue

@@ -8,6 +8,7 @@ import iconImage from '@/assets/images/icon.svg'
 import { Visibility, routes } from '@/plugins/routesLayout'
 import {
   AuthRequestError,
+  ROLE_ADMIN,
   fetchCurrentUser,
   hasRole,
   logout,
@@ -97,8 +98,18 @@ const sidebarRoutes = computed(() =>
     )
   }),
 )
-const firstAuthenticatedSidebarIndex = computed(() =>
-  sidebarRoutes.value.findIndex((item) => item.visible === Visibility.Authenticated),
+const adminSidebarRoutes = computed(() =>
+  sidebarRoutes.value.filter(
+    (item) =>
+      item.visible === Visibility.Authorized &&
+      Array.isArray(item.requiredRoles) &&
+      item.requiredRoles.some((role) => role.trim().toLowerCase() === ROLE_ADMIN),
+  ),
+)
+const primarySidebarRoutes = computed(() =>
+  sidebarRoutes.value.filter(
+    (item) => !adminSidebarRoutes.value.some((adminItem) => adminItem.path === item.path),
+  ),
 )
 const footerRoutes = computed(() => routes.filter((x) => x.visible === Visibility.Footer))
 
@@ -290,6 +301,12 @@ watch(
             </template>
 
             <v-list density="compact" class="account-menu-list">
+              <v-list-item
+                prepend-icon="mdi-lock-reset"
+                title="Passwort ändern"
+                :to="{ name: 'ChangePassword' }"
+              />
+              <v-divider />
               <v-list-item
                 prepend-icon="mdi-logout"
                 :title="isLoggingOut ? 'Abmelden...' : 'Abmelden'"
@@ -316,6 +333,11 @@ watch(
                 title="Zum Dashboard"
                 :to="{ name: 'Dashboard' }"
               />
+              <v-list-item
+                prepend-icon="mdi-lock-reset"
+                title="Passwort ändern"
+                :to="{ name: 'ChangePassword' }"
+              />
               <v-divider />
               <v-list-item
                 prepend-icon="mdi-logout"
@@ -363,13 +385,27 @@ watch(
       </div>
 
       <v-list nav :density="display.mobile.value ? 'default' : 'comfortable'" class="px-1">
-        <template v-for="(item, index) in sidebarRoutes" :key="item.path">
-          <v-divider
-            v-if="firstAuthenticatedSidebarIndex > 0 && index === firstAuthenticatedSidebarIndex"
-            class="my-2 mx-2"
+        <template v-for="item in primarySidebarRoutes" :key="item.path">
+          <v-list-item
+            :to="item.path"
+            :active="route.path === item.path"
+            :prepend-icon="item.icon"
+            :title="item.name"
+            class="hoard-nav-item"
+            rounded="lg"
+            link
           />
+        </template>
+
+        <template v-if="adminSidebarRoutes.length > 0">
+          <v-divider class="my-2 mx-2" />
+          <div class="drawer-section-head">
+            <p class="drawer-kicker hoard-kicker hoard-kicker--xs">Admin</p>
+          </div>
 
           <v-list-item
+            v-for="item in adminSidebarRoutes"
+            :key="item.path"
             :to="item.path"
             :active="route.path === item.path"
             :prepend-icon="item.icon"
@@ -586,6 +622,10 @@ watch(
   border-top: 1px solid color-mix(in srgb, var(--color-border) 90%, white 10%);
 }
 
+.drawer-section-head {
+  padding: var(--space-2) var(--space-3) var(--space-1);
+}
+
 :deep(.hoard-nav-item) {
   min-height: 44px;
 }
@@ -606,6 +646,10 @@ watch(
 }
 
 .hoard-footer {
+  flex: 0 0 auto;
+  height: auto !important;
+  min-height: 0 !important;
+  max-height: 88px;
   padding-inline: var(--space-6);
 }