add: better stripe endpoint

crates/core/src/model/auth.rs

@@ -322,6 +322,9 @@ pub struct UserSettings {
     /// and the following timeline.
     #[serde(default)]
     pub auto_full_unlist: bool,
+    /// Biography shown on `profile/private.lisp` page.
+    #[serde(default)]
+    pub private_biography: String,
 }
 
 fn mime_avif() -> String {