feat(gateway): add tailscale auth + pam

src/gateway/protocol/schema.ts

@@ -77,6 +77,8 @@ export const ConnectParamsSchema = Type.Object(
       Type.Object(
         {
           token: Type.Optional(Type.String()),
+          username: Type.Optional(Type.String()),
+          password: Type.Optional(Type.String()),
         },
         { additionalProperties: false },
       ),