init: 初始化 AssetX 项目仓库

包含 webapp（Next.js 用户端）、webapp-back（Go 后端）、
antdesign（管理后台）、landingpage（营销落地页）、
数据库 SQL 和配置文件。

landingpage/hooks/useCountUp.ts

@@ -0,0 +1,83 @@
+'use client';
+
+import { useState, useEffect, useRef } from 'react';
+
+/**
+ * 数字增长动画 Hook - 进入视口触发，离开视口重置
+ * 使用 requestAnimationFrame 保证与浏览器刷新同步
+ */
+export function useCountUp(end: number, duration: number = 1500, startRangePercent: number = 0.75) {
+  const [mounted, setMounted] = useState(false);
+  const [count, setCount] = useState(end); // 初始值设为目标值，避免 hydration 错误
+  const elementRef = useRef<HTMLDivElement>(null);
+  const startValueRef = useRef<number>(end);
+  const rafRef = useRef<number | null>(null);
+
+  // 客户端挂载后设置随机起始值
+  useEffect(() => {
+    setMounted(true);
+    startValueRef.current = Math.floor(end * (startRangePercent + Math.random() * 0.15));
+    setCount(startValueRef.current);
+  }, [end, startRangePercent]);
+
+  useEffect(() => {
+    if (!mounted) return;
+
+    const cancelAnimation = () => {
+      if (rafRef.current !== null) {
+        cancelAnimationFrame(rafRef.current);
+        rafRef.current = null;
+      }
+    };
+
+    const startAnimation = () => {
+      cancelAnimation();
+
+      const start = startValueRef.current;
+      const startTime = performance.now();
+
+      const tick = (currentTime: number) => {
+        const elapsed = currentTime - startTime;
+        const progress = Math.min(elapsed / duration, 1);
+
+        // easeOutCubic 缓动
+        const easeOutCubic = 1 - Math.pow(1 - progress, 3);
+        const currentCount = Math.floor(start + (end - start) * easeOutCubic);
+
+        setCount(currentCount);
+
+        if (progress < 1) {
+          rafRef.current = requestAnimationFrame(tick);
+        } else {
+          setCount(end); // 确保最终值准确
+          rafRef.current = null;
+        }
+      };
+
+      rafRef.current = requestAnimationFrame(tick);
+    };
+
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting) {
+          startAnimation();
+        } else {
+          cancelAnimation();
+          setCount(startValueRef.current);
+        }
+      },
+      { threshold: 0.1 }
+    );
+
+    if (elementRef.current) {
+      observer.observe(elementRef.current);
+    }
+
+    return () => {
+      observer.disconnect();
+      cancelAnimation();
+    };
+  }, [end, duration, mounted]);
+
+  return { count, elementRef };
+}