I would check out Trilium. It’s a general purpose note taking/knowledge base application but it’s very powerful in how it can be used. You could create a note for each item and attach a photo to the note. Then you can add details and have them searchable.
Open source and has Linux client
Stores data locally and/or syncs to a server
Not sure what Nextcloud is but it is easy to self host
Does not have Android app but it if you self-host the web interface is usable on mobile through the browser
I would check out Trilium. It’s a general purpose note taking/knowledge base application but it’s very powerful in how it can be used. You could create a note for each item and attach a photo to the note. Then you can add details and have them searchable.