Merge pull request 'fix: 修复 Docker Compose 环境下 PostgreSQL 连接失败' (#114) from fix/actions into develop

Reviewed-on: http://8.161.227.145:3000/XEngineers/CamTalk/pulls/114

backend/internal/config/config.go

@@ -152,6 +152,7 @@ func Load() (*Config, error) {
 	v.SetDefault("ai.tts.output_format", "mp3")
 	v.SetDefault("ai.tts.sample_rate", 24000)
 	v.SetDefault("storage.driver", "memory")
+	v.SetDefault("storage.dsn", "")
 	v.SetDefault("log.level", "info")
 	v.SetDefault("log.format", "console")
 	v.SetDefault("auth.access_ttl", 15)