perf(server): fix broadcast loops, avoid locking db on index, eliminate O(N*M) search, and fix db loss

server/src/main.rs

@@ -115,16 +115,22 @@ async fn run_server(state: Arc<MemoryState>) -> Result<(), Box<dyn std::error::E
     let app_state_clone = Arc::clone(&app_state);
     let mut rx = state.activity_tx.subscribe();
     tokio::spawn(async move {
-        while let Ok(msg) = rx.recv().await {
-            let senders: Vec<_> = app_state_clone
-                .clients
-                .read()
-                .unwrap_or_else(|e| e.into_inner())
-                .values()
-                .cloned()
-                .collect();
-            for client_tx in senders {
-                let _ = client_tx.try_send(msg.clone());
+        loop {
+            match rx.recv().await {
+                Ok(msg) => {
+                    let senders: Vec<_> = app_state_clone
+                        .clients
+                        .read()
+                        .unwrap_or_else(|e| e.into_inner())
+                        .values()
+                        .cloned()
+                        .collect();
+                    for client_tx in senders {
+                        let _ = client_tx.try_send(msg.clone());
+                    }
+                }
+                Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
+                Err(tokio::sync::broadcast::error::RecvError::Lagged(_)) => continue,
             }
         }
     });