اضافه شدن قابلیت رندر پی سی بی

frontend/pcb-layers.js

@@ -0,0 +1,9 @@
+/** Native layer identities; drill visibility also depends on its recorded copper span. */
+export function layerVisible(id, span, selected) {
+  if (!selected.has(id)) return false;
+  return id !== '81' || !span.length || span.some(layer => selected.has(layer));
+}
+export function presetLayers(layers, preset) {
+  return new Set(layers.filter(layer => preset === 'all' || layer.id === '0' || layer.id === '81' ||
+    (preset === 'top' ? ['1','33'].includes(layer.id) : ['32','34'].includes(layer.id))).map(layer => layer.id));
+}