fix astro check

frontend/src/scripts/client/Session.ts

@@ -8,15 +8,14 @@ export class Session {
   private readonly terminal: Terminal;
   private readonly fitAddon: FitAddon;
   private readonly relayConnection: RelayConnection;
-  private readonly terminalConnection: TerminalConnection;
 
   constructor(url: string, element: HTMLElement) {
     this.socket = new WebSocket(url);
     this.terminal = new Terminal();
     this.fitAddon = new FitAddon();
     this.initTerminal(element);
     this.relayConnection = new RelayConnection(this.socket, this.terminal);
-    this.terminalConnection = new TerminalConnection(this.relayConnection, this.terminal, this.fitAddon);
+    new TerminalConnection(this.relayConnection, this.terminal, this.fitAddon);
   }
 
   private initTerminal(element: HTMLElement) {

frontend/src/scripts/client/TerminalConnection.ts

@@ -1,12 +1,13 @@
 import type { Terminal } from "@xterm/xterm";
 import type { RelayConnection } from "./RelayConnection.ts";
 import { debounce } from "lodash";
+import type { FitAddon } from "@xterm/addon-fit";
 
 export class TerminalConnection {
   constructor(
     private readonly relayConnection: RelayConnection,
     private readonly terminal: Terminal,
-    private readonly fitAddon,
+    private readonly fitAddon: FitAddon,
   ) {
     this.registerEventListeners();
   }