add config for max views, expiration and advanced

backend/src/status/model.rs

@@ -0,0 +1,10 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+pub struct Status {
+  pub version: String,
+  pub max_size: usize,
+  pub max_views: usize,
+  pub max_expiration: usize,
+  pub allow_advanced: bool,
+}