fix: auth /social-providers endpoint ids (#115)

The `/social-providers` endpoint should return a list of the provider ids, not their names.
This was found when trying to use the microsoft endpoint and the endpoint was returning `"microsoft entraid"`, when the `AuthForm` expects it to just be `"microsoft"`.

packages/auth/src/auth.ts

@@ -84,7 +84,7 @@ export const socialProvidersPlugin = () => ({
         method: "GET",
       },
       async (ctx) =>
-        ctx.json(ctx.context.socialProviders.map((p) => p.name.toLowerCase())),
+        ctx.json(ctx.context.socialProviders.map((p) => p.id.toLowerCase())),
     ),
   },
 });