Fix HealthPage crash: move intradayData query below selectedDay declaration

The useQuery for intradayData referenced selectedDay (a useMemo) before it
was declared in the function body, causing ReferenceError on every render
and breaking the health page entirely.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/pages/HealthPage.jsx

@@ -436,12 +436,6 @@ export default function HealthPage() {
         .then(r => r.data.map(d => ({ ...d, date: d10(d.date) }))),
   })
 
-  const { data: intradayData } = useQuery({
-    queryKey: ['health-intraday', selectedDay?.date],
-    queryFn: () => api.get('/health-metrics/intraday', { params: { date: selectedDay.date } }).then(r => r.data),
-    enabled: !!selectedDay?.date,
-  })
-
   // Trend window (changes with range selector).
   // Dates normalised to YYYY-MM-DD so XAxis values match ReferenceLine x.
   const { data: rawMetrics, isLoading } = useQuery({
@@ -469,6 +463,12 @@ export default function HealthPage() {
     return allDaysSorted.findIndex(d => d.date === selectedDay.date)
   }, [selectedDay, allDaysSorted])
 
+  const { data: intradayData } = useQuery({
+    queryKey: ['health-intraday', selectedDay?.date],
+    queryFn: () => api.get('/health-metrics/intraday', { params: { date: selectedDay.date } }).then(r => r.data),
+    enabled: !!selectedDay?.date,
+  })
+
   const handleDayClick = (dateStr) => setSelectedDateStr(d10(dateStr))
   const goOlder = () => {
     if (selectedIdx < allDaysSorted.length - 1)