Fix viewport bounds getting out of sync at times, like when toggling rulers

frontend/src/utility-functions/viewports.ts

@@ -0,0 +1,14 @@
+import { type Editor } from "@graphite/wasm-communication/editor";
+
+export function updateBoundsOfViewports(editor: Editor, container: HTMLElement) {
+	const viewports = Array.from(container.querySelectorAll("[data-viewport]"));
+	const boundsOfViewports = viewports.map((canvas) => {
+		const bounds = canvas.getBoundingClientRect();
+		return [bounds.left, bounds.top, bounds.right, bounds.bottom];
+	});
+
+	const flattened = boundsOfViewports.flat();
+	const data = Float64Array.from(flattened);
+
+	if (boundsOfViewports.length > 0) editor.handle.boundsOfViewports(data);
+}