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

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

apps/backend/internal/config/config.go

@@ -0,0 +1,37 @@
+package config
+
+import (
+	"os"
+
+	"github.com/joho/godotenv"
+)
+
+type Config struct {
+	Port      string
+	DBHost    string
+	DBPort    string
+	DBUser    string
+	DBPass    string
+	DBName    string
+	JWTSecret string
+}
+
+func Load() *Config {
+	_ = godotenv.Load()
+	return &Config{
+		Port:      getEnv("PORT", "8080"),
+		DBHost:    getEnv("DB_HOST", "localhost"),
+		DBPort:    getEnv("DB_PORT", "5432"),
+		DBUser:    getEnv("DB_USER", "partymix"),
+		DBPass:    getEnv("DB_PASSWORD", "partymix"),
+		DBName:    getEnv("DB_NAME", "partymix"),
+		JWTSecret: getEnv("JWT_SECRET", "change-me-in-production"),
+	}
+}
+
+func getEnv(key, fallback string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return fallback
+}