Meta: Simplify GC heap explorer's class list rendering

We don't need to pass the filter and sort to the render function from
all these locations, the callers always use values from the same
inputs. Instead, just use the values directly from cached references
the input elements.

This fixes the class filter not being applied correctly after a refresh
autofills the old value back into it.

Meta/gc-heap-explorer.html

@@ -1279,6 +1279,9 @@
         const mainApp = document.getElementById('main-app');
         const fileInput = document.getElementById('file-input');
         const loading = document.getElementById('loading');
+        const classSearchInput = document.getElementById('class-search');
+        const rootSearchInput = document.getElementById('root-search');
+        let currentFilterButton = document.querySelector('.filter-btn.active');
 
         // File handling
         dropZone.addEventListener('dragover', (e) => {
@@ -1386,7 +1389,9 @@
             initGraph();
         }
 
-        function renderClassList(filter = '', sortBy = 'count') {
+        function renderClassList() {
+            const filter = classSearchInput.value;
+            const sortBy = currentFilterButton.dataset.sort;
             const list = document.getElementById('class-list');
             const maxCount = Math.max(...Object.values(classStats).map(s => s.count));
 
@@ -1420,7 +1425,8 @@
             `).join('');
         }
 
-        function renderRootList(filter = '') {
+        function renderRootList() {
+            const filter = rootSearchInput.value;
             const list = document.getElementById('root-list');
 
             // Group roots by type
@@ -1481,31 +1487,22 @@
                 });
             });
 
-            document.getElementById('class-search').addEventListener('input', (e) => {
+            classSearchInput.addEventListener('input', renderClassList);
-                renderClassList(e.target.value, getCurrentSort());
+            rootSearchInput.addEventListener('input', renderRootList);
-            });
-
-            document.getElementById('root-search').addEventListener('input', (e) => {
-                renderRootList(e.target.value);
-            });
 
             document.querySelectorAll('.filter-btn').forEach(btn => {
                 btn.addEventListener('click', () => {
-                    document.querySelectorAll('.filter-btn').forEach(b => b.classList.remove('active'));
+                    currentFilterButton.classList.remove('active');
                     btn.classList.add('active');
-                    renderClassList(document.getElementById('class-search').value, btn.dataset.sort);
+                    currentFilterButton = btn;
+                    renderClassList();
                 });
             });
         }
 
-        function getCurrentSort() {
-            const active = document.querySelector('.filter-btn.active');
-            return active ? active.dataset.sort : 'count';
-        }
-
         function selectClass(className) {
             selectedClass = className;
-            renderClassList(document.getElementById('class-search').value, getCurrentSort());
+            renderClassList();
             visualizeClass(className);
         }
 
@@ -1983,7 +1980,7 @@
                 // Also select the class to show it in the graph
                 const className = heapData[decimalAddr].class_name;
                 selectedClass = className;
-                renderClassList(document.getElementById('class-search').value, getCurrentSort());
+                renderClassList();
                 visualizeClass(className);
             } else {
                 alert('Address not found in heap dump');