Revert overly strict token validation in frontend

- Allow null/invalid tokens to be passed to backend
- Backend now handles invalid tokens gracefully
- Maintains original OAuth flow behavior
- Users can vote even with expired tokens in localStorage

src/routes/Vote.svelte

@@ -45,18 +45,12 @@
         try {
             const url = "/api/fetchScenes";
             const token = localStorage.getItem("access_token");
-            const headers = {
-                "Cache-Control": "no-cache",
-            };
-            
-            // Only add Authorization header if we have a valid token
-            if (token) {
-                headers.Authorization = `Bearer ${token}`;
-            }
-            
             const response = await fetch(url, {
                 method: "GET",
-                headers,
+                headers: {
+                    "Cache-Control": "no-cache",
+                    Authorization: `Bearer ${token}`,
+                },
             });
             const result = await response.json();
             if (result.input) {

src/routes/api/fetchScenes/+server.ts

@@ -5,11 +5,7 @@ export const GET: RequestHandler = async ({ request }) => {
     const authHeader = request.headers.get("authorization");
     let accessToken = null;
     if (authHeader && authHeader.startsWith("Bearer ")) {
-        const token = authHeader.substring("Bearer ".length);
-        // Don't use token if it's null, undefined, or empty string
-        if (token && token !== "null" && token !== "undefined") {
-            accessToken = token;
-        }
+        accessToken = authHeader.substring("Bearer ".length);
     }
 
     const url = accessToken