update actix to version 4

backend/src/api.rs

@@ -0,0 +1,25 @@
+use actix_web::{get, web, HttpResponse, Responder};
+use serde::{Deserialize, Serialize};
+
+use crate::note;
+use crate::size::LIMIT;
+
+#[derive(Serialize, Deserialize)]
+struct Status {
+  version: String,
+  max_size: usize,
+}
+
+#[get("/status")]
+async fn status() -> impl Responder {
+  return HttpResponse::Ok().json(Status {
+    version: option_env!("CARGO_PKG_VERSION")
+      .unwrap_or("Unknown")
+      .to_string(),
+    max_size: *LIMIT,
+  });
+}
+
+pub fn init(cfg: &mut web::ServiceConfig) {
+  cfg.service(web::scope("/api").service(note::service()).service(status));
+}