.native-control Opt-out: global select-Style ueberschrieb das System-Native

User-Screenshot: dropdowns sehen immer noch wie pills aus. Grund: das
globale `select { appearance: none; background-image: var(--select-arrow);
border-radius: 999px; ... }` in index.css uebermalte die Inline-Resets von
BarSelect — globale CSS-Specificity gewann.

Fix:
- Neue `.native-control`-Klasse in index.css setzt mit `revert` alle
  pill-Overrides zurueck → WebKit/macOS rendert wieder Default-Combobox
- BarSelect: className="native-control" am <select>
- Custom-Massstab-Input: className="native-control"

Andere Selects im Projekt behalten den pill-Look (Ebenen-/Geschoss-Manager
etc.) — nur die Oberleiste opt-out.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/index.css

@@ -196,6 +196,33 @@ select:hover {
   border-color: var(--text-muted);
 }
 
+/* Opt-out: System-native Chrome (Oberleiste). Setzt die globalen
+   pill/appearance:none Overrides zurueck und ueberlaesst WebKit das
+   Rendering — Standard-macOS-Combobox + Native-Popup-Menue. */
+select.native-control,
+input.native-control {
+  appearance: auto;
+  -webkit-appearance: auto;
+  background: revert;
+  background-image: none;
+  border: revert;
+  border-radius: revert;
+  padding: revert;
+  font: revert;
+  letter-spacing: revert;
+  box-shadow: none;
+}
+select.native-control:hover,
+input.native-control:hover {
+  background: revert;
+  border-color: revert;
+}
+select.native-control:focus,
+input.native-control:focus {
+  box-shadow: revert;
+  border-color: revert;
+}
+
 /* Utility */
 .label-xs {
   font-size: 10px;