refactor(frontend): hoist .header-row, .icons-only, .summary-card to page-shell.css

Settings and Xray pages both carried identical .header-row /
.header-actions / .header-info rules and an identical six-rule
.icons-only block that styles tabbed page navigation. Clients, Inbounds,
and Nodes all carried identical .summary-card padding rules with the
same mobile reduction. None of these are page-specific.

Consolidate:
- .header-row family → page-shell scoped to .settings-page, .xray-page
- .icons-only family → page-shell global (the class is a deliberate
  opt-in marker, no scope needed)
- .summary-card → page-shell scoped to .clients-page, .inbounds-page,
  .nodes-page (also fixes InboundsPage's missing scope — its rule was
  global and would have matched stray .summary-card uses elsewhere)

InboundsPage.css and NodesPage.css became empty after the move so the
files and their per-page imports are deleted.

frontend/src/pages/clients/ClientsPage.css

@@ -3,16 +3,6 @@
   min-width: 100px;
 }
 
-.clients-page .summary-card {
-  padding: 16px;
-}
-
-@media (max-width: 768px) {
-  .clients-page .summary-card {
-    padding: 8px;
-  }
-}
-
 .client-email-list {
   max-height: 280px;
   min-width: 160px;

frontend/src/pages/inbounds/InboundsPage.css

@@ -1,9 +0,0 @@
-.summary-card {
-  padding: 16px;
-}
-
-@media (max-width: 768px) {
-  .summary-card {
-    padding: 8px;
-  }
-}

frontend/src/pages/inbounds/InboundsPage.tsx

@@ -36,7 +36,6 @@ import LazyMount from '@/components/LazyMount';
 const InboundFormModal = lazy(() => import('./InboundFormModal'));
 const InboundInfoModal = lazy(() => import('./InboundInfoModal'));
 const QrCodeModal = lazy(() => import('./QrCodeModal'));
-import './InboundsPage.css';
 
 type RowAction =
   | 'edit'

frontend/src/pages/nodes/NodesPage.css

@@ -1,9 +0,0 @@
-.nodes-page .summary-card {
-  padding: 16px;
-}
-
-@media (max-width: 768px) {
-  .nodes-page .summary-card {
-    padding: 8px;
-  }
-}

frontend/src/pages/nodes/NodesPage.tsx

@@ -17,7 +17,6 @@ import AppSidebar from '@/components/AppSidebar';
 import NodeList from './NodeList';
 import NodeFormModal from './NodeFormModal';
 import { setMessageInstance } from '@/utils/messageBus';
-import './NodesPage.css';
 
 export default function NodesPage() {
   const { t } = useTranslation();

frontend/src/pages/settings/SettingsPage.css

@@ -2,50 +2,6 @@
   margin-bottom: 10px;
 }
 
-.settings-page .header-row {
-  display: flex;
-  flex-wrap: wrap;
-  align-items: center;
-}
-
-.settings-page .header-actions {
-  padding: 4px;
-}
-
-.settings-page .header-info {
-  display: flex;
-  justify-content: flex-end;
-}
-
-.icons-only .ant-tabs-nav {
-  margin-bottom: 8px;
-}
-
-.icons-only .ant-tabs-nav-wrap {
-  width: 100%;
-}
-
-.icons-only .ant-tabs-nav-list {
-  display: flex;
-  width: 100%;
-}
-
-.icons-only .ant-tabs-tab {
-  flex: 1 1 0;
-  justify-content: center;
-  margin: 0;
-  padding: 10px 0;
-}
-
-.icons-only .ant-tabs-tab .anticon {
-  margin: 0;
-  font-size: 18px;
-}
-
-.icons-only .ant-tabs-nav-operations {
-  display: none;
-}
-
 .ldap-no-inbounds {
   margin-top: 6px;
   color: var(--ant-color-text-tertiary);

frontend/src/pages/xray/XrayPage.css

@@ -1,18 +1,3 @@
-.xray-page .header-row {
-  display: flex;
-  flex-wrap: wrap;
-  align-items: center;
-}
-
-.xray-page .header-actions {
-  padding: 4px;
-}
-
-.xray-page .header-info {
-  display: flex;
-  justify-content: flex-end;
-}
-
 .xray-page .restart-icon {
   font-size: 16px;
   cursor: pointer;
@@ -34,32 +19,3 @@
   margin: 0;
   opacity: 0.7;
 }
-
-.xray-page .icons-only .ant-tabs-nav {
-  margin-bottom: 8px;
-}
-
-.xray-page .icons-only .ant-tabs-nav-wrap {
-  width: 100%;
-}
-
-.xray-page .icons-only .ant-tabs-nav-list {
-  display: flex;
-  width: 100%;
-}
-
-.xray-page .icons-only .ant-tabs-tab {
-  flex: 1 1 0;
-  justify-content: center;
-  margin: 0;
-  padding: 10px 0;
-}
-
-.xray-page .icons-only .ant-tabs-tab .anticon {
-  margin: 0;
-  font-size: 18px;
-}
-
-.xray-page .icons-only .ant-tabs-nav-operations {
-  display: none;
-}

frontend/src/styles/page-shell.css

@@ -80,3 +80,64 @@
 .loading-spacer {
   min-height: calc(100vh - 120px);
 }
+
+.settings-page .header-row,
+.xray-page .header-row {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+}
+
+.settings-page .header-actions,
+.xray-page .header-actions {
+  padding: 4px;
+}
+
+.settings-page .header-info,
+.xray-page .header-info {
+  display: flex;
+  justify-content: flex-end;
+}
+
+.icons-only .ant-tabs-nav {
+  margin-bottom: 8px;
+}
+
+.icons-only .ant-tabs-nav-wrap {
+  width: 100%;
+}
+
+.icons-only .ant-tabs-nav-list {
+  display: flex;
+  width: 100%;
+}
+
+.icons-only .ant-tabs-tab {
+  flex: 1 1 0;
+  justify-content: center;
+  margin: 0;
+  padding: 10px 0;
+}
+
+.icons-only .ant-tabs-tab .anticon {
+  margin: 0;
+  font-size: 18px;
+}
+
+.icons-only .ant-tabs-nav-operations {
+  display: none;
+}
+
+.clients-page .summary-card,
+.inbounds-page .summary-card,
+.nodes-page .summary-card {
+  padding: 16px;
+}
+
+@media (max-width: 768px) {
+  .clients-page .summary-card,
+  .inbounds-page .summary-card,
+  .nodes-page .summary-card {
+    padding: 8px;
+  }
+}