- mac_frontmost_window now selects the exact accessibility-focused onscreen window, requiring a unique match and re-checking it, instead of taking the first window in CG order (utility panels used to win)
- add Engine::execute_batch, which runs signed requests in order and stops at the first non-verified result
- ship the TextEdit demonstration example

Amp-Thread-ID: https://ampcode.com/threads/T-01a15710-34fc-736a-a53b-26fae62db0e1
Co-authored-by: Amp <amp@ampcode.com>