Anthropic omits Access-Control-Allow-Origin unless the caller sends
anthropic-dangerous-direct-browser-access, so the web build failed with an
opaque "Could not reach this endpoint from the browser" for the anthropic
provider. @ai-sdk/anthropic does not send the header and neither did our
adapter.
Send it from the browser only. The desktop build routes through tauriFetch
and is not subject to CORS, so it does not need to advertise browser access.
Fixes#436
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
ff31f90de9