把复杂的事，写清楚。

Six genuinely deployable open-source albums compared on phone backup, AI, encryption, permissions, footprint and deployment effort, with a recommendation per scenario.

六个能真正部署的开源相册放在一起对比：手机备份、AI 能力、隐私加密、权限模型、资源占用与部署难度，并按场景给出结论。