As far as future proof goes, Danbooru has been on the web for 15 years and on github for 10 and is still actively developed. There is a web interface and also a

As far as future proof goes, Danbooru has been on the web for 15 years and on github for 10 and is still actively developed. There is a web interface and also a webapi. But the (lack of) access control may be a problem. Maybe with appropriate nginx auth config you can ensure only the family can access it. If you search for it beware NSFW.