fix(frontend): 终端弹框适配与审计实时监控布局优化

- 修复 LiveMonitorDialog 连接中卡死：WebSocket 先连、延后挂载 xterm
- 审计实时监控弹框对齐 WebSSH 布局：92vw 宽、520px 高、支持全屏
- 修复服务器终端弹框右侧黑边：fit 后同步 PTY resize，延迟二次 fit
- 抽取 xterm-utils 公共适配逻辑，统一 ResizeObserver 处理

frontend/src/components/server/TerminalDialog.tsx

@@ -11,6 +11,7 @@ import { FitAddon } from 'xterm-addon-fit';
 import 'xterm/css/xterm.css';
 import { Maximize2, Minimize2, X, Shield} from 'lucide-react';
 import { cn } from '@/lib/utils';
+import { attachTerminalResize, fitTerminal, mountXterm } from '@/lib/xterm-utils';
 import { useUserStore } from '@/store';
 import { credentialApi, serverCredentialApi } from '@/services/api';
 import { toast } from 'sonner';
@@ -127,15 +128,8 @@ export function TerminalDialog({
 
     ws.onopen = () => {
       setConnected(true);
-      if (containerRef.current) {
-        term.open(containerRef.current);
-        requestAnimationFrame(() => {
-          try {
-            fit.fit();
-            term.focus();
-          } catch { /* noop */ }
-        });
-      }
+      // 挂载后 fit + 同步 PTY 尺寸，避免右侧黑边 // Logan.Li
+      mountXterm(term, fit, () => containerRef.current, ws);
     };
 
     ws.onclose = () => {
@@ -158,39 +152,33 @@ export function TerminalDialog({
     };
   }, [open, serverId, authReady]);
 
-  // 用 ResizeObserver 监听容器实际尺寸变化，自动 fit 终端
-  // 这比 window resize 或 setTimeout 更可靠：
-  // - 全屏/窗口切换时容器尺寸在 CSS 过渡期间持续变化，ResizeObserver 每次都会触发
-  // - 不需要猜测延迟时间
+  // 容器尺寸变化时 fit 并同步远端 PTY // Logan.Li
   useEffect(() => {
-    if (!open) return;
-    const container = containerRef.current;
-    if (!container) return;
+    if (!open || !authReady) return;
 
-    let resizeTimer: ReturnType<typeof setTimeout>;
-    const ro = new ResizeObserver(() => {
-      // 防抖：CSS 过渡期间会连续触发多次，合并为最后一次
-      clearTimeout(resizeTimer);
-      resizeTimer = setTimeout(() => {
-        if (fitRef.current && termRef.current && wsRef.current) {
-          try {
-            fitRef.current.fit();
-            termRef.current.focus();
-            const { cols, rows } = termRef.current;
-            if (wsRef.current.readyState === WebSocket.OPEN) {
-              wsRef.current.send(JSON.stringify({ status: 1, cols, rows }));
-            }
-          } catch { /* noop */ }
-        }
-      }, 60);
-    });
+    let cleanup: (() => void) | undefined;
+    let retry = 0;
 
-    ro.observe(container);
-    return () => {
-      clearTimeout(resizeTimer);
-      ro.disconnect();
+    const attach = () => {
+      const container = containerRef.current;
+      const fit = fitRef.current;
+      const term = termRef.current;
+      const ws = wsRef.current;
+      if (!container || !fit || !term) {
+        if (retry++ < 30) requestAnimationFrame(attach);
+        return;
+      }
+      cleanup = attachTerminalResize(container, fit, term, ws);
+      try {
+        fitTerminal(fit, term, ws);
+      } catch {
+        /* noop */
+      }
     };
-  }, [open]);
+
+    attach();
+    return () => cleanup?.();
+  }, [open, authReady, fullscreen]);
 
   return (
     <Dialog open={open} onOpenChange={onOpenChange}>
@@ -204,7 +192,7 @@ export function TerminalDialog({
             ? '!max-w-none !w-screen !h-screen !rounded-none !translate-x-0 !translate-y-0 !left-0 !top-0'
             : ''
         )}
-        style={fullscreen ? { maxWidth: '100vw', width: '100vw', height: '100vh' } : { maxWidth: '900px', width: '90vw' }}
+        style={fullscreen ? { maxWidth: '100vw', width: '100vw', height: '100vh' } : { maxWidth: '960px', width: '92vw' }}
       >
         <DialogTitle className="sr-only">终端 - {serverName}</DialogTitle>
         <DialogDescription className="sr-only">SSH 终端连接</DialogDescription>
@@ -267,8 +255,8 @@ export function TerminalDialog({
         {authReady && (
           <div
             ref={containerRef}
-            className="bg-[#0a0e14]"
-            style={{ height: fullscreen ? 'calc(100vh - 49px)' : '480px' }}
+            className="xterm-terminal-host"
+            style={{ height: fullscreen ? 'calc(100vh - 49px)' : '520px' }}
           />
         )}
       </DialogContent>