Fix Neovim connection deadlock by dropping NVIM_CONN lock across await boundary

server/src/main.rs

@@ -249,7 +249,8 @@ fn run_server(state: Arc<MemoryState>) -> Result<(), Box<dyn std::error::Error>>
                 post(
                     |headers: axum::http::HeaderMap, State(state): State<Arc<AppState>>| async move {
                         let token_path = state.handler.state.base_dir.join("admin.token");
-                        let expected_token = std::fs::read_to_string(&token_path)
+                        let expected_token = tokio::fs::read_to_string(&token_path)
+                            .await
                             .unwrap_or_default()
                             .trim()
                             .to_string();