Add Brave CDP automation, replace Oracle browser mode

Connects to user's running Brave via Chrome DevTools Protocol
to automate ChatGPT interaction. Uses puppeteer-core to open a
tab, send the prompt, wait for response, and extract the result.

No cookies, no separate profiles, no copy/paste. Just connects
to the browser where the user is already logged in.

One-time setup: relaunch Brave with --remote-debugging-port=9222

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

node_modules/yargs/build/lib/utils/is-promise.js

@@ -0,0 +1,5 @@
+export function isPromise(maybePromise) {
+    return (!!maybePromise &&
+        !!maybePromise.then &&
+        typeof maybePromise.then === 'function');
+}