Kept the prototype out of search engines in the Website service.

Services/Website/Sources/App/Extensions/ConfigReader+Properties.swift

@@ -264,6 +264,16 @@ package extension ConfigReader {
         )
     }
 
+    /// Whether search engines may index the site, read from the `site.indexable` key.
+    ///
+    /// Off by default: the prototype holds demo data, and a sign-in anyone can use. While off, every response is marked `noindex`.
+    var isIndexable: Bool {
+        bool(
+            forKey: .Site.indexable,
+            default: false
+        )
+    }
+
     /// The origin passkeys are bound to, read from the `passkeys.origin` key.
     var passkeysOrigin: String {
         string(