[Feature] Support for Nested Albums (Album Hierarchies)

🧭 Feature Proposal: Support for Nested Albums (Album Hierarchies) 🙏 Intro – A Respectful Discussion First Hi everyone, I'd like to propose a technically focused feature discussion around supporting nested albums (album hierarchies) in Immich. I understand that this topic has come up before and often sparks strong opinions. So before diving in, I just want to say: > 🚩 Let’s keep this a respectful and collaborative technical discussion. > The goal here is not to push a personal agenda, but to explore if and how nested albums could be added in a way that aligns with Immich’s vision, technical constraints, and design principles. --- 🌱 Summary Currently, Immich supports flat albums only. This proposal explores introducing album hierarchies, where albums can contain other albums, allowing users (especially families or archivists) to better organize large photo collections. Use cases include: • Organizing albums by year/event (e.g. Family > 202…