Added Checkbox Controller javascript

assets/javascripts/checkbox_controller.js

@@ -0,0 +1,23 @@
+document.addEventListener("turbo:load", () => {
+  const selectAllBox = document.getElementById("select-all-batches");
+  const checkboxes = document.querySelectorAll(".item-checkbox");
+
+  if (selectAllBox) {
+    selectAllBox.addEventListener("change", function() {
+      checkboxes.forEach((checkbox) => {
+        checkbox.checked = this.checked;
+      });
+    });
+
+    // Optional: Uncheck "Select All" if an individual box is unchecked
+    checkboxes.forEach((checkbox) => {
+      checkbox.addEventListener("change", () => {
+        if (!checkbox.checked) {
+          selectAllBox.checked = false;
+        } else if (Array.from(checkboxes).every(c => c.checked)) {
+          selectAllBox.checked = true;
+        }
+      });
+    });
+  }
+});