Set a larger max-age to the current HTTP cache-control header /api/assets/

[chengguangnan]

The HTTP header on the thumbnail URL (/api/assets/:asset_id/thumbnail?size=thumbnail) sets Cache-Control max-age to 1 day which seems too short. I use immich occasionally and usually across different days, but every time I use it, it has too re-fech thumbnails, which slows down a lot even I'm using a Mac M1 for hosting.

For a thumbnail, it seems to me a forever cache makes sense. The user is alway able to use a hard refresh to invalidate the cache I assume.