feat(motion-kit): render the Studio and capture site pages as Claude Motion films

motion-kit/browser.ts

@@ -0,0 +1,22 @@
+import { chromium, type Browser } from 'playwright-core';
+
+/**
+ * Chrome as installed on this machine, or the Chromium at `CHROMIUM_PATH`.
+ * Never downloads a browser.
+ */
+export const launchBrowser = async (): Promise<Browser> => {
+    const executablePath = process.env.CHROMIUM_PATH;
+
+    try {
+        return await chromium.launch(executablePath ? { executablePath } : { channel: 'chrome' });
+    } catch (error) {
+        throw new Error(
+            executablePath
+                ? `motion-kit: no browser starts at CHROMIUM_PATH=${executablePath}. ` +
+                      'Point it at a Chrome or Chromium executable, or unset it to use the installed Chrome.'
+                : 'motion-kit: Google Chrome is not installed where Playwright looks for it. ' +
+                      'Install Chrome, or set CHROMIUM_PATH to a Chrome or Chromium executable.',
+            { cause: error },
+        );
+    }
+};