Not sure! But it's a great question to be asking. It's a bit abstract, aspirational, and hard to describe - but the vision/dream is there. I'd assume desktop is the first goal, to dedicate specific hardware to this. Then eventually I'd love to see this make it to the full vision of a nostrOS on mobile.
I'm a die hard grapheneOS fan, and have been for a while. I'm not sure I would use a nostrOS on mobile unless it was just as secure and privacy oriented. However, that is exactly my longterm vision.
The pixel devices that run Graphene today have secure hardware that could generate nostr keys etc and keep them locked down in a proven way. The vision pushes that one layer deeper than typical browser extensions or Amber for example: signer baked into the OS, key born and held in the secure element. No more app download, but a more direct protocol interaction, straight to nsites and clients etc.
So; OS generates and holds the key within Titan M2 secure elements -> nsites are the UI surface -> signing is a protocol interaction rather than an app permission.
