Schema ReTrace added (create schematic diagrams from netlists).

docs/schema/history.js

@@ -0,0 +1,28 @@
+// ── Undo history ─────────────────────────────────────────────
+// Kept separate to avoid circular imports between interaction.js and ui.js.
+import { S }				 from './state.js';
+import { routeWires } from './layout.js';
+import { render }			from './draw.js';
+
+export function pushHistory() {
+	S.history.push(JSON.stringify(
+		S.components.map(c => ({ id: c.id, x: c.x, y: c.y, rotation: c.rotation, flipX: c.flipX }))
+	));
+	if (S.history.length > 60) S.history.shift();
+}
+
+export function undo() {
+	if (!S.history.length) {
+		import('./ui.js').then(({ toast }) => toast('Nothing to undo', 'warn'));
+		return;
+	}
+	JSON.parse(S.history.pop()).forEach(s => {
+		const c = S.components.find(x => x.id === s.id);
+		if (!c) return;
+		c.x = s.x; c.y = s.y; c.rotation = s.rotation; c.flipX = s.flipX;
+	});
+	// routeWires() fully syncs all geometry (including restored rotations)
+	// and positions into WireBender before calling routeAll().
+	routeWires();
+	import('./ui.js').then(({ toast }) => toast('Undone'));
+}