Initial commit: party-mix-app with prefetch cache, audio preload optimizations

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/backend/main.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"log"
+
+	"github.com/toyffee/party-mix/internal/config"
+	"github.com/toyffee/party-mix/internal/database"
+	"github.com/toyffee/party-mix/internal/router"
+)
+
+func main() {
+	cfg := config.Load()
+	db := database.Connect(cfg)
+	r := router.New(db, cfg.JWTSecret)
+	log.Printf("Party Mix backend starting on :%s", cfg.Port)
+	if err := r.Run(":" + cfg.Port); err != nil {
+		log.Fatalf("server failed: %v", err)
+	}
+}