add: service edit date + browser session ids

crates/core/src/model/auth.rs

@@ -70,6 +70,16 @@ pub struct User {
     /// used an invite code.
     #[serde(default)]
     pub was_purchased: bool,
+    /// This value is updated for every **new** littleweb browser session.
+    ///
+    /// This means the user can only have one of these sessions open at once
+    /// (unless this token is stored somewhere with a way to say we already have one,
+    /// but this does not happen yet).
+    ///
+    /// Without this token, the user can still use the browser, they just cannot
+    /// view pages which require authentication (all `$` routes).
+    #[serde(default)]
+    pub browser_session: String,
 }
 
 pub type UserConnections =
@@ -357,6 +367,7 @@ impl User {
             achievements: Vec::new(),
             awaiting_purchase: false,
             was_purchased: false,
+            browser_session: String::new(),
         }
     }