Add loading overlay while scenes initialize

- Show a spinner overlay that fades out once Cesium globe
  data is ready, with a 1s minimum and 8s timeout
- Expose a ready promise on CesiumGlobe resolved after country
  and city data load
- Remove temporary inspect script

src/main.js

@@ -8,3 +8,16 @@ for (const ev of ['copy', 'cut', 'contextmenu']) {
 // 启动应用
 const app = new App();
 window.__app = app; // 便于调试
+
+// 加载界面：等三个视图初始化完成（最少展示 1 秒，最多等 8 秒）后淡出
+const t0 = Date.now();
+const MIN_DISPLAY = 1000;
+Promise.race([
+  app.globe.ready,
+  new Promise((r) => setTimeout(r, 8000)),
+]).then(() => {
+  const wait = Math.max(0, MIN_DISPLAY - (Date.now() - t0));
+  setTimeout(() => {
+    document.getElementById('loading').classList.add('hidden');
+  }, wait);
+});

src/scene/CesiumGlobe.js

@@ -69,6 +69,8 @@ export class CesiumGlobe {
     this.selected = -1;
     this._created = false;
     this._visible = false;
+    this._pendingData = 2; // 国家边界 + 城市数据
+    this.ready = new Promise((resolve) => { this._resolveReady = resolve; });
   }
 
   ensureCreated() {
@@ -316,6 +318,8 @@ export class CesiumGlobe {
       }
     } catch (err) {
       console.warn('[CesiumGlobe] 行政区划加载失败：', err);
+    } finally {
+      this._dataReady();
     }
   }
 
@@ -362,6 +366,15 @@ export class CesiumGlobe {
         },
       });
     }
+    this._dataReady();
+  }
+
+  _dataReady() {
+    this._pendingData--;
+    if (this._pendingData <= 0 && this._resolveReady) {
+      this._resolveReady();
+      this._resolveReady = null;
+    }
   }
 
   setSelected(index) {

src/styles.css

@@ -52,6 +52,29 @@ html, body {
   background: #0c0906; opacity: 0; transition: opacity 0.18s ease;
 }
 
+/* 加载界面 */
+#loading {
+  position: fixed; inset: 0; z-index: 1000;
+  display: flex; align-items: center; justify-content: center;
+  background: #14100d;
+  transition: opacity 0.6s ease;
+}
+#loading.hidden { opacity: 0; pointer-events: none; }
+.loading-box { display: flex; flex-direction: column; align-items: center; gap: 18px; }
+.spinner {
+  width: 54px; height: 54px;
+  border: 3px solid rgba(201, 162, 39, 0.22);
+  border-top-color: #c9a227;
+  border-radius: 50%;
+  animation: spin 0.9s linear infinite;
+}
+@keyframes spin { to { transform: rotate(360deg); } }
+.loading-text {
+  font-family: var(--serif);
+  font-size: 14px; letter-spacing: 0.3em;
+  color: rgba(230, 216, 182, 0.7);
+}
+
 /* 顶部标题 */
 .hud { position: absolute; z-index: 5; }
 .top-left { top: 22px; left: 26px; }