Write failing tests for APIs.do integration.
Test cases:
- $.api provides typed service accessors
- $.integrate() stores credentials securely
- $.api.emails.send() works
- $.api.texts.send() works
- $.api.calls.initiate() works
- $.api.stripe.* works with Payments.do
- $.api.slack.send() works
- OAuth flow completes successfully
- API errors handled gracefully
- Rate limiting respected
Write failing tests for APIs.do integration.
Test cases: