
PiGallery is what you’re asking for, but you should consider Immich, it’s very simple to setup and you’ll get tons of features more that are extremely useful. I get you want something simple, but I don’t feel Immich is hard to setup or maintain, and it’s the difference between a simple photo gallery and google photos.

All art is political, because it depends on the politics of the society it was created.
First we need to agree on a definition of political, in general I think a good definition is “dealing with the structure, organization, and administration of the state”.
So, a cave painting, just like any art that shows you how people live in a society is exposing the structure, organization and possibly administration of the state, which is the very definition of politics.
Here’s the thing, any art is either based on reality or fictitious. Art based on reality like portraits or biographies are political because they show you the society as it is. On the other hand fictitious art shows you failures or limitations of the society they were written in, or sometimes they offer metaphors to draw parallels or point at stuff in the society they were written.
If you think art is not political I ask you to find me some piece of art that does not deal with the structure, organization or administration of the state.