An OAuth adapter for DSH

Key features

• An OAuth account page for the DSH Web profile.
• DSH integrates pi-ai through the @deepseek-ai/dsh-llm-pi-ai adapter, but does not provide an OAuth entry point.
• The adapter has only been tested with DSH 0.1.1-rc.2
• compatibility with future versions is need to test.
• @edge-sky/dsh-oauth-adapter exposes pi-ai's existing provider login flows through the DSH Authorization Service.