Fix cache bypass scope bug causing 500 error

response variable was scoped inside if(!bypassCache) block but referenced
outside. Changed to const response in the R2 fetch section and conditionally
cache based on bypassCache flag.

src/worker.js

@@ -588,12 +588,17 @@ export default {
         headers.set('ETag', object.etag);
       }
 
-      response = new Response(object.body, { headers });
+      const response = new Response(object.body, { headers });
 
-      ctx.waitUntil(Promise.all([
-        cache.put(cacheKey, response.clone()),
-        recordUsage(env, customer, object.size)
-      ]));
+      // 캐시 바이패스가 아닌 경우에만 캐시에 저장
+      if (!bypassCache) {
+        ctx.waitUntil(Promise.all([
+          cache.put(cacheKey, response.clone()),
+          recordUsage(env, customer, object.size)
+        ]));
+      } else {
+        ctx.waitUntil(recordUsage(env, customer, object.size));
+      }
 
       return response;