style(index): 优化首页样式与布局

- 重新设计首页背景色与容器安全区适配
- 优化Hero Banner区域增加圆角遮罩效果
- 调整Hero Grid菜单区样式，去除背景色实现透明效果
- 新增公告条样式，自定义样式替代NutUI NoticeBar
- 优化底部购买按钮样式，调整高度及阴影
- 统一首页通用section的左右边距，融合TrustSection和ContactSection样式

.workbuddy/expert-history.json

@@ -0,0 +1,17 @@
+{
+  "version": 2,
+  "sessions": {
+    "8469bdd5894b41e1ba171a40f33d6a83": [
+      {
+        "expertId": "UiDesigner",
+        "name": "Sam",
+        "profession": "UI设计师",
+        "avatarUrl": "https://acc-1258344699.cos.accelerate.myqcloud.com/workbuddy/experts/avatars/01-Design/UiDesigner/UiDesigner.png",
+        "promptUrl": "https://acc-1258344699.cos.accelerate.myqcloud.com/workbuddy/experts/experts/01-Design/UiDesigner/UiDesigner_zh.md",
+        "usedAt": 1775709039214,
+        "industryId": "all"
+      }
+    ]
+  },
+  "lastUpdated": 1775711001059
+}