add: ProfileStyle products

crates/core/src/model/auth.rs

@@ -101,11 +101,20 @@ pub struct User {
     /// already applied this purchase.
     #[serde(default)]
     pub checkouts: Vec<String>,
+    /// The IDs of products to be applied to the user's profile.
+    #[serde(default)]
+    pub applied_configurations: Vec<(AppliedConfigType, usize)>,
 }
 
 pub type UserConnections =
     HashMap<ConnectionService, (ExternalConnectionInfo, ExternalConnectionData)>;
 
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
+pub enum AppliedConfigType {
+    /// An HTML `<style>` snippet.
+    StyleSnippet,
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub enum ThemePreference {
     Auto,
@@ -417,6 +426,7 @@ impl User {
             ban_expire: 0,
             coins: 0,
             checkouts: Vec::new(),
+            applied_configurations: Vec::new(),
         }
     }