✨ feat(jvm-ui): 完善 JVM 工作台与监控入口

- 新增 JVM 持续监控仪表盘、图表、状态卡和详情面板

- 统一概览、资源浏览、审计页面的 JVM 工作台布局

- Sidebar 和 TabManager 支持监控入口、诊断入口兜底和上下文切换

- 补充前端状态模型、展示文案和组件回归测试

frontend/src/utils/jvmMonitoringPresentation.ts

@@ -0,0 +1,176 @@
+import type {
+  JVMMonitoringPoint,
+  JVMMonitoringRecentGCEvent,
+  JVMMonitoringSessionState,
+} from "../types";
+
+const METRIC_LABELS: Record<string, string> = {
+  "heap.used": "堆内存",
+  "heap.non_heap": "非堆内存",
+  "gc.count": "垃圾回收次数",
+  "gc.time": "垃圾回收耗时",
+  "gc.events": "最近垃圾回收事件",
+  "thread.count": "线程数",
+  "thread.states": "线程状态",
+  "class.loading": "类加载",
+  "cpu.process": "进程 CPU",
+  "cpu.system": "系统 CPU",
+  "memory.rss": "进程物理内存",
+  "memory.virtual": "进程虚拟内存",
+};
+
+export type JVMMonitoringProviderMode = JVMMonitoringSessionState["providerMode"];
+
+const MONITORING_PROVIDER_MODES: JVMMonitoringProviderMode[] = [
+  "jmx",
+  "endpoint",
+  "agent",
+];
+
+const THREAD_STATE_LABELS: Record<string, string> = {
+  NEW: "新建",
+  RUNNABLE: "可运行",
+  BLOCKED: "阻塞",
+  WAITING: "等待中",
+  TIMED_WAITING: "限时等待",
+  TERMINATED: "已终止",
+};
+
+const timeFormatter = new Intl.DateTimeFormat("zh-CN", {
+  hour: "2-digit",
+  minute: "2-digit",
+  second: "2-digit",
+  hour12: false,
+});
+
+export type MonitoringChartPoint = JVMMonitoringPoint & {
+  timeLabel: string;
+};
+
+export const resolveMonitoringMetricLabel = (metric: string): string =>
+  METRIC_LABELS[String(metric || "").trim()] || String(metric || "").trim();
+
+export const resolveThreadStateLabel = (state?: string | null): string => {
+  const normalized = String(state || "").trim().toUpperCase();
+  return THREAD_STATE_LABELS[normalized] || String(state || "").trim();
+};
+
+export const formatMonitoringTime = (timestamp?: number): string => {
+  if (typeof timestamp !== "number" || !Number.isFinite(timestamp)) {
+    return "--";
+  }
+  return timeFormatter.format(new Date(timestamp));
+};
+
+export const formatBytes = (value?: number): string => {
+  if (typeof value !== "number" || !Number.isFinite(value) || value < 0) {
+    return "--";
+  }
+  const units = ["B", "KB", "MB", "GB", "TB"];
+  let next = value;
+  let unitIndex = 0;
+  while (next >= 1024 && unitIndex < units.length - 1) {
+    next /= 1024;
+    unitIndex += 1;
+  }
+  const precision = next >= 100 || unitIndex === 0 ? 0 : next >= 10 ? 1 : 2;
+  return `${next.toFixed(precision)} ${units[unitIndex]}`;
+};
+
+export const formatMonitoringAxisBytes = (value?: number): string => formatBytes(value);
+
+export const formatPercent = (value?: number): string => {
+  if (typeof value !== "number" || !Number.isFinite(value) || value < 0) {
+    return "--";
+  }
+  return `${(value * 100).toFixed(1)}%`;
+};
+
+export const formatCompactNumber = (value?: number): string => {
+  if (typeof value !== "number" || !Number.isFinite(value)) {
+    return "--";
+  }
+  return value.toLocaleString("zh-CN");
+};
+
+export const formatDurationMs = (value?: number): string => {
+  if (typeof value !== "number" || !Number.isFinite(value) || value < 0) {
+    return "--";
+  }
+  return `${Math.round(value)}ms`;
+};
+
+export const normalizeMonitoringProviderMode = (
+  value: unknown,
+  fallback: JVMMonitoringProviderMode = "jmx",
+): JVMMonitoringProviderMode => {
+  const normalized = String(value || "").trim().toLowerCase();
+  if (MONITORING_PROVIDER_MODES.includes(normalized as JVMMonitoringProviderMode)) {
+    return normalized as JVMMonitoringProviderMode;
+  }
+  return MONITORING_PROVIDER_MODES.includes(fallback) ? fallback : "jmx";
+};
+
+export const buildMonitoringAvailabilityText = ({
+  missingMetrics,
+  providerWarnings,
+}: Pick<JVMMonitoringSessionState, "missingMetrics" | "providerWarnings">): string => {
+  const fragments: string[] = [];
+
+  if (Array.isArray(missingMetrics) && missingMetrics.length > 0) {
+    fragments.push(
+      `缺失指标：${missingMetrics
+        .map((metric) => resolveMonitoringMetricLabel(metric))
+        .join("、")}`,
+    );
+  }
+
+  if (Array.isArray(providerWarnings) && providerWarnings.length > 0) {
+    fragments.push(`监控来源告警：${providerWarnings.join("；")}`);
+  }
+
+  if (fragments.length === 0) {
+    return "当前监控会话未发现明显降级。";
+  }
+
+  return fragments.join(" | ");
+};
+
+export const formatRecentGCLabel = (
+  event: JVMMonitoringRecentGCEvent,
+): string => {
+  const parts = [
+    formatMonitoringTime(event.timestamp),
+    String(event.name || "").trim(),
+    typeof event.durationMs === "number" ? `${event.durationMs}ms` : "",
+    String(event.cause || "").trim(),
+  ].filter(Boolean);
+
+  return parts.join(" · ");
+};
+
+export const buildMonitoringChartPoints = (
+  points: JVMMonitoringPoint[] = [],
+): MonitoringChartPoint[] =>
+  points.map((point) => ({
+    ...point,
+    timeLabel: formatMonitoringTime(point.timestamp),
+  }));
+
+export const extractThreadStateRows = (
+  point?: JVMMonitoringPoint,
+): Array<{ state: string; label: string; count: number }> =>
+  Object.entries(point?.threadStateCounts || {})
+    .map(([state, count]) => ({
+      state,
+      label: resolveThreadStateLabel(state),
+      count: Number(count) || 0,
+    }))
+    .sort((left, right) => right.count - left.count);
+
+export const monitoringMetricAvailable = (
+  session: Pick<JVMMonitoringSessionState, "availableMetrics"> | undefined,
+  metric: string,
+): boolean =>
+  Array.isArray(session?.availableMetrics) &&
+  session.availableMetrics.includes(metric);