feat: Redis查询结果优化 — 复制按钮+JSON自动格式化+语义化列名

1. GET/HGET/TTL等单值命令: columns改为[key,value]替代[command,result]
2. DBSIZE等无key命令保持[command,result]格式
3. 前端添加复制按钮(Clipboard API), 2秒反馈
4. JSON值自动检测并格式化显示(whitespace-pre-wrap)
5. 结果区最大高度350px→500px
6. cost_ms字段兼容处理

frontend/src/pages/QueriesPage.tsx

@@ -5,7 +5,7 @@ import {
   StarOff, Download, Search, ArrowUpDown, Database, Table2,
   ArrowUp, ArrowDown, Eye, Hash, PanelLeftClose, Columns3,
   KeyRound, FolderOpen, Server, Zap, ClipboardPaste,
-  History, PanelRightClose, PanelRightOpen,
+  History, PanelRightClose, PanelRightOpen, Copy, Check,
 } from 'lucide-react';
 // Card components replaced by design system utility classes
 import { useActionPermission } from '@/hooks/useAuth';
@@ -264,6 +264,46 @@ export default function QueriesPage() {
     downloadCSV(`query_result_${new Date().toISOString().slice(0, 19).replace(/:/g, '-')}.csv`, exportToCSV(result.columns, result.rows));
   }, [result]);
 
+  /* ---- Copy Result ---- */
+  const [copied, setCopied] = useState(false);
+  const handleCopyResult = useCallback(() => {
+    if (!result) return;
+    let text = '';
+    if (result.rows?.length && result.columns?.length) {
+      // Format as readable text
+      const lines = result.rows.map((row: Record<string, unknown>) =>
+        result.columns.map((col: string) => {
+          const val = String(row[col] ?? '');
+          // Try to pretty-format JSON values
+          try {
+            const parsed = JSON.parse(val);
+            if (typeof parsed === 'object') return JSON.stringify(parsed, null, 2);
+          } catch { /* not JSON */ }
+          return val;
+        }).join('\t')
+      );
+      text = [result.columns.join('\t'), ...lines].join('\n');
+    } else {
+      text = JSON.stringify(result, null, 2);
+    }
+    navigator.clipboard.writeText(text).then(() => {
+      setCopied(true);
+      setTimeout(() => setCopied(false), 2000);
+    });
+  }, [result]);
+
+  /* ---- Smart cell value formatter (detect JSON) ---- */
+  const formatCellValue = useCallback((val: unknown) => {
+    const str = String(val ?? '');
+    try {
+      const parsed = JSON.parse(str);
+      if (typeof parsed === 'object' && parsed !== null) {
+        return { text: JSON.stringify(parsed, null, 2), isJson: true };
+      }
+    } catch { /* not JSON */ }
+    return { text: str, isJson: false };
+  }, []);
+
   /* ---- History ---- */
   const toggleFavorite = useCallback((id: number) => {
     setHistory(prev => {
@@ -439,21 +479,27 @@ export default function QueriesPage() {
                   查询结果
                 </span>
                 <div className="flex items-center gap-3 text-xs dg-text-secondary">
-                  <span className="flex items-center gap-1"><Clock className="w-3 h-3" />{result.execution_time_ms}ms</span>
+                  <span className="flex items-center gap-1"><Clock className="w-3 h-3" />{result.execution_time_ms || result.cost_ms || 0}ms</span>
                   <span>{result.rows?.length || 0} 行</span>
                   <span>{result.columns?.length || 0} 列</span>
                   {result.rows && result.rows.length > 0 && (
-                    <button onClick={handleExportResult}
-                      className="dg-btn dg-btn-ghost dg-btn-sm">
-                      <Download className="w-3 h-3" />导出 CSV
-                    </button>
+                    <>
+                      <button onClick={handleCopyResult}
+                        className="dg-btn dg-btn-ghost dg-btn-sm gap-1">
+                        {copied ? <><Check className="w-3 h-3 text-green-400" /><span className="text-green-400">已复制</span></> : <><Copy className="w-3 h-3" />复制</>}
+                      </button>
+                      <button onClick={handleExportResult}
+                        className="dg-btn dg-btn-ghost dg-btn-sm">
+                        <Download className="w-3 h-3" />导出 CSV
+                      </button>
+                    </>
                   )}
                 </div>
               </div>
             </div>
             <div className="p-0">
               {result.columns && result.columns.length > 0 ? (
-                <div ref={resultContainerRef} onScroll={handleResultScroll} className="overflow-auto max-h-[350px]">
+                <div ref={resultContainerRef} onScroll={handleResultScroll} className="overflow-auto max-h-[500px]">
                   <table className="w-full text-sm">
                     <thead className="sticky top-0 z-10">
                       <tr className="dg-table-header">
@@ -481,9 +527,12 @@ export default function QueriesPage() {
                             {result.columns.map(col => {
                               const isSensitive = sensitiveKeywords.some(k => col.toLowerCase().includes(k));
                               const cellValue = row[col] ?? '';
+                              const { text: displayText, isJson } = formatCellValue(cellValue);
                               return (
-                                <td key={col} className="px-3 py-2 text-xs max-w-[200px] truncate" title={String(cellValue)}>
-                                  {isSensitive ? <span className="text-yellow-400 italic">{maskData(String(cellValue))}</span> : String(cellValue)}
+                                <td key={col} className={`px-3 py-2 text-xs ${isJson ? 'max-w-[400px] whitespace-pre-wrap break-all font-mono text-[11px] leading-relaxed' : 'max-w-[200px] truncate'}`} title={String(cellValue)}>
+                                  {isSensitive ? <span className="text-yellow-400 italic">{maskData(String(cellValue))}</span> :
+                                   isJson ? <span className="text-blue-300">{displayText}</span> :
+                                   String(cellValue)}
                                 </td>
                               );
                             })}