Nextcloud with a few addons. Now this might look like overkill for your use case but I get the impression that you might want to go further in future.

Stock NC gets you a very solid general purpose document management system and with a few addons, you basically get self hosted SharePoint and OneDrive without the baggage. The images/pictures side of things has seen quite a lot of development and with some addons you get image classification with fairly minimal effort.

The system as a whole will quite happily handle many 100,000 files with pretty rubbish hardware, if you are happy to wait for batch jobs to run or you throw more hardware at it and speed up the job schedules.

NC has a stock phone app which works very well these days, including camera folder uploads. There are several more apps that integrate with the main one to add optional functionality. For example notes and voip.

It is a very large and mature setup with loads of documentation and hence extensible by a determined hacker if something is missing.