Expose a configurable default proxy for SUB2API, resolve the proxy once,
persist the proxy_id in state, and reuse it across auth URL generation,
code exchange, and account creation so one OAuth flow stays on one proxy.
Constraint: Upstream GitHub permission is READ, so publication must use a fork PR
Rejected: Push to origin | current GitHub viewer permission does not allow upstream branch publication
Rejected: Resolve proxy independently in later steps | could drift from the proxy chosen at auth URL generation
Confidence: high
Scope-risk: moderate
Reversibility: clean
Tested: npm test passed 183/183
Not-tested: Manual browser extension flow against a live SUB2API deployment
- Replaced individual step imports with a centralized step registry in background.js
- Created separate modules for each registration step: open-chatgpt, submit-signup-email, fill-password, fetch-signup-code, fill-profile, oauth-login, fetch-login-code, confirm-oauth, platform-verify
- Updated tests to reflect changes in step imports and added new tests for step registry functionality