add file system persistence of record API calls to avoid hammering the discogs API

cmd/serve/main.go

@@ -129,16 +129,10 @@ func main() {
 		log.Fatalln(err)
 	}
 	log.Printf("latest migration: %d; migrations run: %d", latest, run)
-	discogsCache, err := database.NewDiscogsCache(c.DiscogsToken, time.Hour*24, "delta.mu.alpha")
+	discogsCache, err := database.NewDiscogsCache(c.DiscogsToken, time.Hour*24, c.DiscogsUser, c.DiscogsPersist, c.DiscogsCacheFile)
 	if err != nil {
 		log.Fatalln(err)
 	}
-	go func() {
-		err := discogsCache.FlushCache(context.Background())
-		if err != nil {
-			log.Printf("error loading discogs content: %v", err)
-		}
-	}()
 	r := &Router{
 		static: f,
 		lib:    lib,