persisted selection of child and time range when switching between pages. Also added automatic total sleep time scaling on vertical axis

src/baby_monitor/static/diapers.html

@@ -267,9 +267,15 @@
 
       let allDiaperChanges = [];
       let allChildren = [];
-      let currentDaysRange = 7;
+      let currentDaysRange = parseInt(localStorage.getItem("lastDiaperTimeRange")) || 7;
       let selectedChildId = null; // null means "All Children"
 
+      // Restore last selected child from localStorage
+      const lastChildId = localStorage.getItem("lastDiaperChildFilter");
+      if (lastChildId && lastChildId !== "all") {
+        selectedChildId = parseInt(lastChildId);
+      }
+
       // Load diaper changes data
       async function loadDiaperChanges() {
         try {
@@ -311,12 +317,14 @@
 
       function onDaysRangeChange(event) {
         currentDaysRange = parseInt(event.target.value);
+        localStorage.setItem("lastDiaperTimeRange", currentDaysRange);
         displayDiaperChanges(allDiaperChanges);
       }
 
       function onChildChange(event) {
         selectedChildId =
           event.target.value === "all" ? null : parseInt(event.target.value);
+        localStorage.setItem("lastDiaperChildFilter", event.target.value);
         displayDiaperChanges(allDiaperChanges);
       }