feat(frontend): UI P0 PageHeader + 身份三卡 + 专线抽屉密度

按设计纸落地全站页头规范、飞书 OIDC 状态/凭据/地址同步三卡，以及专线列表筛选独立行、行点击 480 抽屉与启停+更多操作列。

frontend/src/locales/en-US.json

@@ -230,7 +230,9 @@
     "viewTasks": "View Tasks",
     "noTasks": "No task history",
     "trafficTrend": "Traffic Trend",
-    "noTrafficData": "No traffic data yet (waiting for samples…)"
+    "noTrafficData": "No traffic data yet (waiting for samples…)",
+    "pageDescription": "Manage VPN tunnels and runtime status",
+    "title": "Tunnels"
   },
   "oidcGuide": {
     "title": "Feishu / OIDC browser authentication",
@@ -648,7 +650,19 @@
     "loadFailed": "Could not load identity settings",
     "saved": "Identity settings saved",
     "saveFailed": "Could not save identity settings",
-    "pageDescription": "Configure Feishu or OIDC identity (app credentials, tenant, callbacks, and directory sync). Per-tunnel admission stays on the tunnel editor."
+    "pageDescription": "Configure Feishu app credentials, OIDC issuer, and directory sync.",
+    "credentialsTitle": "Credentials",
+    "addressSyncTitle": "Addresses & sync",
+    "tagEnabled": "Enabled",
+    "tagDisabled": "Disabled",
+    "tagTlsOk": "Entry ready",
+    "tagTlsPending": "Entry pending",
+    "tagGatewayOk": "Gateway synced",
+    "tagGatewayPending": "Gateway pending",
+    "tagDirSynced": "Directory synced",
+    "tagDirIdle": "Directory idle",
+    "retryGateway": "Retry gateway sync",
+    "goPublicEntry": "Open public entry"
   },
   "settings": {
     "pageDescription": "Manage account security, the public gateway, and server setup.",