WIP Add settings/about pane

app/components/settings-pane.gjs

@@ -0,0 +1,20 @@
+import Component from '@glimmer/component';
+import { on } from '@ember/modifier';
+import Icon from '#components/icon';
+
+export default class SettingsPane extends Component {
+  <template>
+    <div class="sidebar settings-pane">
+      <div class="sidebar-header">
+        <h2>Settings</h2>
+        <button type="button" class="close-btn" {{on "click" @onClose}}>
+          <Icon @name="x" @size={{20}} @color="#333" />
+        </button>
+      </div>
+
+      <div class="sidebar-content">
+        <p>Settings content placeholder...</p>
+      </div>
+    </div>
+  </template>
+}