Unified Sign-in
Choose a provider, then we send the user back to the original site.
This auth center is designed for your own site portfolio. Each relying site keeps its own local session after the code exchange.
Same email does not mean same identity across providers. For safety, this system does not auto-merge Google, GitHub, or Apple accounts by email alone.
Available providers
Google is enabled now. GitHub and Apple are reserved in the provider adapter layer and can be turned on later.
This page is usually opened from a relying site via `GET /authorize`. The required client and redirect parameters are missing right now, so sign-in is disabled.