fix: mobile task creation button reliability

- Add novalidate to task-form to prevent browser validation quirks
- Add explicit click handler for Save button that triggers
  form submission via dispatched event for mobile compatibility

static/js/tasks.js

@@ -350,6 +350,9 @@ document.addEventListener("DOMContentLoaded", () => {
     document.getElementById("task-modal-close").addEventListener("click", closeTaskModal);
     document.getElementById("task-modal-cancel").addEventListener("click", closeTaskModal);
     document.getElementById("task-form").addEventListener("submit", handleTaskSubmit);
+    document.getElementById("task-save-btn").addEventListener("click", (e) => {
+        document.getElementById("task-form").dispatchEvent(new Event("submit", { cancelable: true }));
+    });
 
     document.getElementById("side-panel-close").addEventListener("click", closeSidePanel);
     document.getElementById("save-task-btn").addEventListener("click", saveTask);