feat(SubTabContainer): 支持自定义 Suspense fallback

- SubTabConfig 添加 fallback 属性
- 财务全景/盈利预测配置骨架屏 fallback
- 解决点击 Tab 先显示 Spinner 再显示骨架屏的问题

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/components/SubTabContainer/index.tsx

@@ -45,6 +45,8 @@ export interface SubTabConfig {
   name: string;
   icon?: IconType | ComponentType;
   component?: ComponentType<any>;
+  /** 自定义 Suspense fallback（如骨架屏） */
+  fallback?: React.ReactNode;
 }
 
 /**
@@ -314,14 +316,16 @@ const SubTabContainer: React.FC<SubTabContainerProps> = memo(({
                 {shouldRender && Component ? (
                   <Suspense
                     fallback={
-                      <Center py={20}>
-                        <Spinner
-                          size="lg"
-                          color={DEEP_SPACE.textGold}
-                          thickness="3px"
-                          speed="0.8s"
-                        />
-                      </Center>
+                      tab.fallback || (
+                        <Center py={20}>
+                          <Spinner
+                            size="lg"
+                            color={DEEP_SPACE.textGold}
+                            thickness="3px"
+                            speed="0.8s"
+                          />
+                        </Center>
+                      )
                     }
                   >
                     <Component {...componentProps} />