Add fullscreen and preview modes

- Add --fullscreen flag for macOS native fullscreen (AppleScript)
- Add --preview flag to highlight elements before actions
- Add --preview-delay to configure highlight duration
- Update README with new options

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@saiden/browse",
-  "version": "0.2.13-pre.0",
+  "version": "0.2.13",
   "description": "Headless browser automation for Claude Code using Playwright WebKit",
   "type": "module",
   "main": "dist/index.js",