fix(UI): Profile 取消按钮样式、HotEvents 轮播箭头、Dashboard 按钮优化

- Profile: 取消按钮添加深色主题样式 (color, borderColor, hover)
- HotEvents: 轮播箭头添加 user-select: none 防止连续点击选中文本
- Dashboard: "查看更多"按钮改为图标按钮 (IconButton + FiPlus)

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

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

src/views/Profile/ProfilePage.js

@@ -208,6 +208,10 @@ export default function ProfilePage() {
                             <Button
                                 leftIcon={<CloseIcon />}
                                 variant="outline"
+                                colorScheme="gray"
+                                color="gray.300"
+                                borderColor="gray.500"
+                                _hover={{ bg: 'gray.700', borderColor: 'gray.400' }}
                                 onClick={() => {
                                     setIsEditing(false);
                                     setFormData({