v1.5.7 — 用户中心布局优化：卡片同行排列 + 滚动条收进页面

优化 / Improved

中文：

用户中心卡片布局调整：
- 「有效期至」与「年度周期」并排同一行——额度总览改为固定 3 列网格（6 卡 = 3×2），窄窗口自动降 2 列仍保持同行
- 「出品」与「合作伙伴」并排同一行，与版本信息卡片视觉对齐
窗口滚动条收进页面：不再使用浏览器窗口右缘滚动，改由页面内容区内部滚动——滚动条移至 1200px 版心内侧，细窄深色圆角样式，与深色主题融合，hover 变亮
切换页面时内容宽度恒定，3D 预览画布不抖动

English:

User Center card layout:
- "Valid Until" and "Annual Cycle" now sit side by side on the same row — quota overview uses a fixed 3-column grid (6 cards = 3×2), auto-collapsing to 2 columns on narrow windows while keeping them on one row
- "Produced By" and "Partners" now share one row, visually aligned with the version info cards
Window scrollbar moved inside the page: scrolling now happens inside the content area instead of the browser window — the scrollbar sits at the inner edge of the 1200px content column, styled as a slim dark rounded bar that fits the dark theme and brightens on hover
Content width stays constant when switching pages, so the 3D preview canvas no longer jitters