fix(mp): setTimeout 无清理修复 — useSafeTimeout hook + 10 页面接入

新增 useSafeTimeout hook，页面隐藏时自动清理所有定时器。
10 个页面接入：daily-monitoring、exchange、family-add、
health/input、prescription detail/create、dialysis detail/create、
appointment detail/create。所有 fire-and-forget setTimeout 替换为
safeSetTimeout，避免页面切走后定时器回调在错误上下文执行。

apps/miniprogram/src/hooks/useSafeTimeout.ts

@@ -0,0 +1,23 @@
+import { useRef, useCallback } from 'react';
+import { useDidHide } from '@tarojs/taro';
+
+export function useSafeTimeout() {
+  const timers = useRef<ReturnType<typeof setTimeout>[]>([]);
+
+  const safeSetTimeout = useCallback((fn: () => void, ms: number) => {
+    const id = setTimeout(() => {
+      timers.current = timers.current.filter((t) => t !== id);
+      fn();
+    }, ms);
+    timers.current.push(id);
+  }, []);
+
+  const clearAll = useCallback(() => {
+    timers.current.forEach(clearTimeout);
+    timers.current = [];
+  }, []);
+
+  useDidHide(() => clearAll());
+
+  return { safeSetTimeout, clearAll };
+}