add proper error and disconnect handling

error handling shows you the error and offers the ability to reload;
disconnect handling shows you that the page will reload in a few seconds.
it uses exponential backoff with some random sprinkled into it to prevent overwhelming the server once people's clients decide to reconnect.

crates/rkgk/src/live_reload.rs

@@ -4,12 +4,17 @@ use axum::{routing::get, Router};
 use tokio::time::sleep;
 
 pub fn router<S>() -> Router<S> {
-    Router::new()
-        .route("/stall", get(stall))
-        .route("/back-up", get(back_up))
-        .with_state(())
+    let router = Router::new().route("/back-up", get(back_up));
+
+    // The endpoint for immediate reload is only enabled on debug builds.
+    // Release builds use the exponential backoff system that detects is the WebSocket is closed.
+    #[cfg(debug_assertions)]
+    let router = router.route("/stall", get(stall));
+
+    router.with_state(())
 }
 
+#[cfg(debug_assertions)]
 async fn stall() -> String {
     loop {
         // Sleep for a day, I guess. Just to uphold the connection forever without really using any

crates/rkgk/src/main.rs

@@ -18,7 +18,6 @@ mod api;
 mod config;
 mod haku;
 mod id;
-#[cfg(debug_assertions)]
 mod live_reload;
 mod login;
 pub mod schema;
@@ -102,8 +101,7 @@ async fn fallible_main() -> eyre::Result<()> {
         .nest_service("/static", ServeDir::new(paths.target_dir.join("static")))
         .nest("/api", api::router(api));
 
-    #[cfg(debug_assertions)]
-    let app = app.nest("/dev/live-reload", live_reload::router());
+    let app = app.nest("/auto-reload", live_reload::router());
 
     let port: u16 = std::env::var("RKGK_PORT")
         .unwrap_or("8080".into())