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/bare-os/lib/errors.js

@@ -0,0 +1,22 @@
+module.exports = class OSError extends Error {
+  constructor(msg, code, fn = OSError) {
+    super(`${code}: ${msg}`)
+    this.code = code
+
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this, fn)
+    }
+  }
+
+  get name() {
+    return 'OSError'
+  }
+
+  static UNKNOWN_SIGNAL(msg) {
+    return new OSError(msg, 'UNKNOWN_SIGNAL', OSError.UNKNOWN_SIGNAL)
+  }
+
+  static TITLE_OVERFLOW(msg) {
+    return new OSError(msg, 'TITLE_OVERFLOW', OSError.TITLE_OVERFLOW)
+  }
+}