fix(k8s): YAML 弹框 Portal 到 body 修复居中偏移

PageTransition 的 transform 会使 fixed 弹框相对页面定位而非视口，
YamlViewer 尺寸较大时容易跑出可视区。统一用 ModalOverlay Portal。

frontend/src/components/kubernetes/ResourceVisualEditor.tsx

@@ -2,6 +2,7 @@
 import { useState, useEffect, useCallback } from 'react';
 import { X, Save, Loader2, Plus, Trash2, FileText, Network, Shield, Database, ChevronRight} from 'lucide-react';
 import { Button } from '@/components/ui/button';
+import { ModalOverlay } from '@/components/ui/modal-overlay';
 import { Input } from '@/components/ui/input';
 import { Label } from '@/components/ui/label';
 import { Textarea } from '@/components/ui/textarea';
@@ -132,8 +133,11 @@ export function ResourceVisualEditor({ clusterCode, namespace, resource, name, o
   const MetaIcon = meta.icon;
 
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60" onClick={onClose}>
-      <div className="bg-[var(--dg-bg-primary)] border border-[var(--dg-border)] rounded-xl w-[90vw] max-w-3xl max-h-[85vh] flex flex-col shadow-2xl" onClick={e => e.stopPropagation()}>
+    <ModalOverlay onClose={onClose}>
+      <div
+        className="bg-[var(--dg-bg-primary)] border border-[var(--dg-border)] rounded-xl w-[90vw] max-w-3xl max-h-[85vh] flex flex-col shadow-2xl"
+        onClick={(e) => e.stopPropagation()}
+      >
         {/* Header */}
         <div className="flex items-center justify-between p-4 border-b border-[var(--dg-border)]">
           <div className="flex items-center gap-2">
@@ -206,7 +210,7 @@ export function ResourceVisualEditor({ clusterCode, namespace, resource, name, o
           )}
         </div>
       </div>
-    </div>
+    </ModalOverlay>
   );
 }
 

frontend/src/components/kubernetes/YamlImportDialog.tsx

@@ -2,6 +2,7 @@
 import { useState } from 'react';
 import { X, Upload, Loader2 } from 'lucide-react';
 import { Button } from '@/components/ui/button';
+import { ModalOverlay } from '@/components/ui/modal-overlay';
 import { useToast } from '@/hooks/use-toast';
 import { kubernetesApi } from '@/api';
 import CodeMirror from '@uiw/react-codemirror';
@@ -36,7 +37,7 @@ export function YamlImportDialog({ clusterCode, onClose, onApplied }: YamlImport
   };
 
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60" onClick={onClose}>
+    <ModalOverlay onClose={onClose}>
       <div
         className="bg-[var(--dg-bg-primary)] border border-[var(--dg-border)] rounded-xl w-[92vw] max-w-4xl max-h-[85vh] flex flex-col shadow-2xl"
         onClick={(e) => e.stopPropagation()}
@@ -71,6 +72,6 @@ export function YamlImportDialog({ clusterCode, onClose, onApplied }: YamlImport
           </Button>
         </div>
       </div>
-    </div>
+    </ModalOverlay>
   );
 }

frontend/src/components/kubernetes/YamlViewer.tsx

@@ -4,6 +4,7 @@
 import { useState, useEffect, useMemo} from 'react';
 import { X, Copy, Check, Save, Loader2, Sparkles} from 'lucide-react';
 import { Button } from '@/components/ui/button';
+import { ModalOverlay } from '@/components/ui/modal-overlay';
 import { useToast } from '@/hooks/use-toast';
 import { kubernetesApi } from '@/api';
 import { cleanYAML } from './k8s-yaml-utils';
@@ -186,10 +187,13 @@ export function YamlViewer({ clusterCode, namespace, resource, name, onClose, on
     );
   }
 
-  // 弹窗模式（原有行为）
+  // 弹窗模式 — Portal 到 body，避免 PageTransition transform 导致偏移 // Logan.Li
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60" onClick={onClose}>
-      <div className="bg-slate-900 border border-slate-700 rounded-xl w-[92vw] max-w-5xl h-[88vh] flex flex-col shadow-2xl" onClick={e => e.stopPropagation()}>
+    <ModalOverlay onClose={onClose}>
+      <div
+        className="bg-slate-900 border border-slate-700 rounded-xl w-[92vw] max-w-5xl max-h-[85vh] flex flex-col shadow-2xl"
+        onClick={(e) => e.stopPropagation()}
+      >
         {/* Header */}
         <div className="flex items-center justify-between p-4 border-b border-slate-700">
           <div>
@@ -260,6 +264,6 @@ export function YamlViewer({ clusterCode, namespace, resource, name, onClose, on
           )}
         </div>
       </div>
-    </div>
+    </ModalOverlay>
   );
 }

frontend/src/components/ui/modal-overlay.tsx

@@ -0,0 +1,24 @@
+// ModalOverlay — Portal 到 body，避免父级 transform 导致 fixed 弹框偏移 // Logan.Li
+import { createPortal } from 'react-dom';
+
+interface ModalOverlayProps {
+  onClose: () => void;
+  children: React.ReactNode;
+  /** 遮罩 z-index，默认高于 Sidebar/Header */
+  zIndex?: number;
+}
+
+export function ModalOverlay({ onClose, children, zIndex = 100 }: ModalOverlayProps) {
+  return createPortal(
+    <div
+      className="fixed inset-0 overflow-y-auto bg-black/60"
+      style={{ zIndex }}
+      onClick={onClose}
+    >
+      <div className="flex min-h-full items-center justify-center p-4">
+        {children}
+      </div>
+    </div>,
+    document.body,
+  );
+}