fix: 修复所有首页板块 pin 滚动不连贯问题

🐛 问题根源:
每个板块有两套独立的 ScrollTrigger 在同一个元素上：
- 入场动画用独立的 scrollTrigger
- pin 效果用 ScrollTrigger.create
两者互相冲突，导致空白间隙和动画跳变

✅ 修复方案:
将所有板块的入场动画和 pin 滚动合并为一个统一时间线（timeline），
确保动画从 pin 开始到结束完全连续，无空白区

🔧 修复的 6 个板块:
1. HomeTestimonials - 标题入场 + 卡片逐张切换（淡入淡出）
2. HomeServices - 标题入场 + 卡片飞入归位 + 逐张聚焦
3. HomeAchievements - 逐个成就项展示（前一个淡出，后一个淡入）
4. HomeTechStack - 内容入场 + 标签散开 + 球体旋转
5. HomeProcess - 标题入场 + 线条绘制 + 步骤逐个出现 + 横向滚动
6. HomeUpdates - 标题入场 + 卡片分批出现

🎯 效果:
- pin 期间动画完全连续，无空白间隙
- 入场和 pin 共享同一个 timeline
- scrub: 0.5 让滚动更平滑
- 每个板块到下一个板块无缝过渡

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/components/home/HomeServices.vue

@@ -202,106 +202,70 @@ onMounted(async () => {
   if (!rootRef.value || !headerRef.value) return
 
   ctx = gsap.context(() => {
-    // 标题动画
-    gsap.fromTo(headerRef.value,
-      { autoAlpha: 0, y: 50 },
-      {
-        scrollTrigger: {
-          trigger: headerRef.value,
-          start: 'top 80%',
-          toggleActions: 'play none none reverse'
-        },
-        autoAlpha: 1,
-        y: 0,
-        duration: 1,
-        ease: 'power3.out'
-      }
-    )
-
-    // Pin 效果：固定板块，逐张卡片聚焦展示
-    const totalCards = services.length
-    const timeline = gsap.timeline()
-
-    // 初始：所有卡片从四周飞入并归位
+    // 初始状态
+    gsap.set(headerRef.value, { autoAlpha: 0, y: 50 })
+    const positions = [
+      { x: -200, y: -200, rotate: -15 },
+      { x: 0, y: -200, rotate: 10 },
+      { x: 200, y: -200, rotate: -15 },
+      { x: -200, y: 200, rotate: 15 },
+      { x: 0, y: 200, rotate: -10 },
+      { x: 200, y: 200, rotate: 15 }
+    ]
     cardElements.value.forEach((card, index) => {
       if (!card) return
-
-      const positions = [
-        { x: -200, y: -200, rotate: -15 },
-        { x: 0, y: -200, rotate: 10 },
-        { x: 200, y: -200, rotate: -15 },
-        { x: -200, y: 200, rotate: 15 },
-        { x: 0, y: 200, rotate: -10 },
-        { x: 200, y: 200, rotate: 15 }
-      ]
-      const startPos = positions[index]
-
-      gsap.set(card, {
-        autoAlpha: 0,
-        x: startPos.x,
-        y: startPos.y,
-        scale: 0.8,
-        rotateZ: startPos.rotate,
-      })
-
-      // 第一屏：所有卡片飞入归位
-      timeline.to(card, {
-        autoAlpha: 1,
-        x: 0,
-        y: 0,
-        scale: 1,
-        rotateZ: 0,
-        duration: 1,
-        ease: 'back.out(1.2)',
-      }, index * 0.1)
+      const p = positions[index]
+      gsap.set(card, { autoAlpha: 0, x: p.x, y: p.y, scale: 0.8, rotateZ: p.rotate })
     })
 
-    // 后续屏：每次聚焦一张卡片（放大），其他缩小
-    for (let focus = 0; focus < totalCards; focus++) {
-      timeline.addLabel(`focus-${focus}`, focus + 1)
+    // 统一时间线
+    const totalCards = services.length
+    const tl = gsap.timeline()
 
+    // 第一屏：标题入场 + 所有卡片飞入归位
+    tl.to(headerRef.value, { autoAlpha: 1, y: 0, duration: 0.8, ease: 'power3.out' }, 0)
+    cardElements.value.forEach((card, index) => {
+      if (!card) return
+      tl.to(card, {
+        autoAlpha: 1, x: 0, y: 0, scale: 1, rotateZ: 0,
+        duration: 1, ease: 'back.out(1.2)',
+      }, 0.2 + index * 0.1)
+    })
+
+    // 后续屏：逐张聚焦
+    for (let focus = 0; focus < totalCards; focus++) {
+      const pos = 1.5 + focus
       cardElements.value.forEach((card, index) => {
         if (!card) return
-
-        timeline.to(card, {
+        tl.to(card, {
           scale: index === focus ? 1.05 : 0.85,
           autoAlpha: index === focus ? 1 : 0.4,
-          zIndex: index === focus ? 10 : 1,
-          duration: 0.6,
-          ease: 'power2.out',
-        }, `focus-${focus}`)
-
-        // 聚焦的卡片翻转展示背面
+          duration: 0.6, ease: 'power2.out',
+        }, pos)
         if (index === focus) {
-          timeline.call(() => handleCardHover(focus, true), [], `focus-${focus}`)
+          tl.call(() => handleCardHover(focus, true), [], pos)
         } else {
-          timeline.call(() => handleCardHover(index, false), [], `focus-${focus}`)
+          tl.call(() => handleCardHover(index, false), [], pos)
         }
       })
     }
 
-    // 最后：恢复所有卡片正常状态
-    timeline.addLabel('reset')
+    // 最后：恢复正常
+    const resetPos = 1.5 + totalCards
     cardElements.value.forEach((card, index) => {
       if (!card) return
-      timeline.to(card, {
-        scale: 1,
-        autoAlpha: 1,
-        zIndex: 1,
-        duration: 0.5,
-        ease: 'power2.out',
-      }, 'reset')
-      timeline.call(() => handleCardHover(index, false), [], 'reset')
+      tl.to(card, { scale: 1, autoAlpha: 1, duration: 0.5, ease: 'power2.out' }, resetPos)
+      tl.call(() => handleCardHover(index, false), [], resetPos)
     })
 
     ScrollTrigger.create({
       trigger: rootRef.value,
       start: 'top top',
-      end: () => `+=${(totalCards + 2) * window.innerHeight}`,
+      end: () => `+=${(totalCards + 3) * window.innerHeight}`,
       pin: true,
-      scrub: true,
+      scrub: 0.5,
       anticipatePin: 1,
-      animation: timeline,
+      animation: tl,
     })
   }, rootRef.value)
 })