fix(ui): 切换日期后数字不更新，卡片显示的是前一天的数据

useCountUp 只靠 requestAnimationFrame 推进，没有兜底。帧不来的时候
（后台标签页、被节流的 webview）setDisplay 一次都不会调用，组件继续
渲染上一个值——往前翻一天，标题的日期变了，但每一个数字还停在前一天。
不是动画没播，是把另一天的数据当成这一天理直气壮地显示出来。

实测（造的数据）：08-24 → 08-23 → 08-22 三天，三张卡片全都显示 8,826，
而真实值是 8,826 / 10,232 / 10,715。

- 动画结束时间点加一个 setTimeout 兜底，保证最终值一定落地
- document.hidden 时直接跳过动画
- from 引用在收敛时同步更新，避免动画被打断后从错误的起点继续

动画是装饰，数字不是。

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

client/src/lib/motion.ts

@@ -36,11 +36,19 @@ export function useCountUp(value: number | null, durationMs = 650): number | nul
   const reduced = usePrefersReducedMotion();
   const [display, setDisplay] = useState<number | null>(value);
   const frame = useRef<number>();
+  const settleTimer = useRef<number>();
   const from = useRef(0);
 
   useEffect(() => {
-    if (value == null || reduced) {
+    const settle = () => {
       setDisplay(value);
+      from.current = value ?? 0;
+    };
+
+    // Nothing to animate towards, or the viewer asked for no motion. Also
+    // covers a hidden tab, where requestAnimationFrame does not run at all.
+    if (value == null || reduced || document.hidden) {
+      settle();
       return;
     }
 
@@ -52,12 +60,23 @@ export function useCountUp(value: number | null, durationMs = 650): number | nul
       const t = Math.min(1, (now - start) / durationMs);
       setDisplay(origin + delta * easeOut(t));
       if (t < 1) frame.current = requestAnimationFrame(tick);
-      else from.current = value;
+      else settle();
     };
 
     frame.current = requestAnimationFrame(tick);
+
+    /* The animation is decoration; the number is not.
+       This used to be rAF alone, so when frames never arrived — a
+       backgrounded tab, a throttled webview — `setDisplay` was never called
+       and the card kept rendering the *previous* value. Stepping back a day
+       changed the date in the header while every figure stayed on the day
+       before: not a missing animation, but the wrong data shown confidently.
+       The timer guarantees the final value lands either way. */
+    settleTimer.current = window.setTimeout(settle, durationMs + 250);
+
     return () => {
       if (frame.current) cancelAnimationFrame(frame.current);
+      window.clearTimeout(settleTimer.current);
     };
   }, [value, durationMs, reduced]);