Clickable home page stat cards; clean up nav; add buttons on list pages; move export/import to home

static/app.js

@@ -61,6 +61,27 @@ function metaSelectChanged(sel, inputId) {
     if (e.key === 'Escape' && modal.classList.contains('open')) closeModal();
   });
 
+  // Apply URL params as initial filter state on battery_list and device_list
+  document.addEventListener('DOMContentLoaded', function() {
+    var params = new URLSearchParams(window.location.search);
+    var statusParam = params.get('status');
+    if (statusParam !== null) {
+      var statusSel = document.getElementById('filter-status');
+      if (statusSel && typeof applyFilters === 'function') {
+        statusSel.value = statusParam;
+        applyFilters();
+      }
+    }
+    var fillParam = params.get('fill');
+    if (fillParam !== null) {
+      var fillSel = document.getElementById('filter-fill');
+      if (fillSel && typeof applyDeviceFilters === 'function') {
+        fillSel.value = fillParam;
+        applyDeviceFilters();
+      }
+    }
+  });
+
   // Global handler: forms with data-confirm attribute
   document.addEventListener('submit', function(e) {
     var form = e.target;