feat(energy): 氢能总览加载骨架屏，缓解 1-2s 初始等待

之前数据回来前只显示一行「加载中…」纯文本，1-2 秒等待体感差。
新增 HydrogenOverviewSkeleton：
  - 4 张 KPI 卡占位（含标题/数值/副信息行）
  - Top5 横向条形图占位（5 行 圆点 + 站名 + 渐变条 + 数值）
  - 区域占比环 + 图例占位
  - 底部蓝色脉冲点 +「正在加载氢能总览…」
全部用 animate-pulse，结构与真实页面保持一致，避免回填时跳动。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/modules/energy/HydrogenOverview.tsx

@@ -57,7 +57,7 @@ export default function HydrogenOverview() {
     return <div className="bg-red-50 text-red-600 rounded-2xl border border-red-100 p-4 text-sm">加载失败：{error}</div>;
   }
   if (!data) {
-    return <div className="bg-white rounded-2xl border border-slate-100 shadow-sm p-6 text-center text-slate-400 text-sm">加载中…</div>;
+    return <HydrogenOverviewSkeleton />;
   }
   const k = data.kpi;
   const top5 = data.top5;
@@ -204,3 +204,72 @@ export default function HydrogenOverview() {
     </div>
   );
 }
+
+function HydrogenOverviewSkeleton() {
+  return (
+    <div className="flex flex-col gap-3 animate-pulse">
+      {/* 顶部说明条 */}
+      <div className="bg-white rounded-xl border border-slate-100 px-3 py-2">
+        <div className="h-3 w-44 bg-slate-100 rounded" />
+      </div>
+
+      {/* 4 张 KPI 卡 */}
+      <div className="grid grid-cols-2 md:grid-cols-4 gap-3">
+        {Array.from({ length: 4 }).map((_, i) => (
+          <div key={i} className="bg-gradient-to-br from-slate-50 to-slate-100/60 rounded-2xl border border-slate-100 shadow-sm p-4 flex flex-col gap-3">
+            <div className="h-3 w-16 bg-slate-200/70 rounded" />
+            <div className="h-7 w-24 bg-slate-200 rounded" />
+            <div className="space-y-1.5 mt-1">
+              <div className="h-2.5 w-20 bg-slate-100 rounded" />
+              <div className="h-2.5 w-24 bg-slate-100 rounded" />
+            </div>
+          </div>
+        ))}
+      </div>
+
+      <div className="grid grid-cols-1 md:grid-cols-2 gap-3">
+        {/* Top5 占位 */}
+        <div className="bg-white rounded-2xl border border-slate-100 shadow-sm p-4">
+          <div className="flex items-center justify-between mb-3">
+            <div className="h-4 w-32 bg-slate-100 rounded" />
+            <div className="h-3 w-12 bg-slate-100 rounded" />
+          </div>
+          <div className="space-y-3">
+            {[100, 78, 56, 40, 28].map((w, i) => (
+              <div key={i} className="flex items-center gap-3">
+                <div className="w-5 h-5 rounded-full bg-slate-200" />
+                <div className="h-3 w-32 bg-slate-100 rounded" />
+                <div className="flex-1 h-4 rounded-md bg-gradient-to-r from-slate-200 to-slate-100" style={{ maxWidth: `${w}%` }} />
+                <div className="h-3 w-12 bg-slate-100 rounded" />
+              </div>
+            ))}
+          </div>
+        </div>
+
+        {/* 区域占比环 占位 */}
+        <div className="bg-white rounded-2xl border border-slate-100 shadow-sm p-4 flex flex-col gap-3">
+          <div className="h-4 w-28 bg-slate-100 rounded" />
+          <div className="flex items-center gap-3">
+            <div className="w-1/2 h-[200px] flex items-center justify-center">
+              <div className="w-32 h-32 rounded-full border-[18px] border-slate-100" />
+            </div>
+            <div className="flex-1 space-y-2">
+              {Array.from({ length: 5 }).map((_, i) => (
+                <div key={i} className="flex items-center gap-2">
+                  <div className="w-2 h-2 rounded-full bg-slate-200" />
+                  <div className="h-3 w-16 bg-slate-100 rounded" />
+                  <div className="h-3 w-10 bg-slate-100 rounded ml-auto" />
+                </div>
+              ))}
+            </div>
+          </div>
+        </div>
+      </div>
+
+      <div className="text-center text-[11px] text-slate-400 font-bold flex items-center justify-center gap-1.5">
+        <span className="inline-block w-1.5 h-1.5 rounded-full bg-blue-400 animate-pulse" />
+        正在加载氢能总览…
+      </div>
+    </div>
+  );
+}