When discussing the life story (fictional/non-fictional) of an inanimate object (like a brick not AI), is it appropriate to claim this endeavor as an autobiography of an inanimate object, when it seems like a first-person perspective of the same?
You can claim it is anything you want; you are writing a fantasy about an inanimate object that can cogitate, observe its surroundings, etc.
I would consider it no different than a first-person tale of a ghost that cannot have any effect on the material world; let's say it can only think logically, feel emotions, discover new knowledge; and relate it's mental state in words on the page, but it cannot do a thing about any of that, it cannot take any action.
So, like the typical third-person narrator of a book, the ghost can relate the story of things going on around it, but can take no action to affect the course of any action. (putting aside telekinetic ghosts).
In effect you are granting intelligence and emotions to a brick, or a teapot, or a wedding ring passed down through generations, and it (in first-person) relates the stories of the people it has seen, from its own perspective. It is like an invisible spy camera, a receiver only.
I could see how that could be an effective story, an object (like a teapot) has a finite life that can be much longer than a human's, and it is also an interesting restriction to place on the narrator, the teapot may be moved about but always must be within "earshot" of the events it relates.
It would make sense to call such a story an autobiography of the object. It doesn't explain how the autobiography was ever told, but it is also never explained in millions of books how a third-person narrator knows everything that happened in a book! So it doesn't have to make any literal sense. Call it an autobiography.
You have two choices here.
If the object is truly inanimate and there are no surprises, then you are writing a history of the object.
If the object is anthropomorphized (think Disney talking teacups), you can call it a biography. If you are writing in first person from the point of view of the object, then it is an autobiography.
Outside this dichotomy, you have stylistic choices. There is a famous short story (I can't remember the name and it's not coming up on searches, if you know it, please edit it in) about a piano slowly decaying after being left on a beach by migrants who couldn't carry it to their home (not related to the movie The Piano).
While the piano here never does anything a piano in the real world couldn't do, we feel for it as if it was alive. The author's haunting narrative turns this inanimate object into a character. The main character. In this case, you might be able to say biography vs just history.