fix: remove unused panel variable in main.test.ts

frontend/src/main.test.ts

@@ -95,7 +95,6 @@ import "../src/main";
 
 describe("chat toggle", () => {
   it("toggles chat panel visibility", () => {
-    const panel = document.getElementById("chat-panel")!;
     const toggle = document.getElementById("chat-toggle")!;
 
     expect(toggle.textContent).toBe("Hide Chat");