Fairphone? https://www.fairphone.com/the-fairphone-gen-6#f_slide_1

But also, I doubt any polity would have its sovereignty undermined if their general-purpose computing hardware doesn't fit into their pockets.

You mean like the dozens of micro laptops/emulator handhelds from china that can all run linux or hobbyist custom roms?

Gonna have to post the storage dimensions of your preferred pockets.

My recently-purchased Google Pixel 10 Pro has an unlockable bootloader. (Although it may be locked if you buy it through a provider).

And, for a nominal one-time payment, you can register as a developer, and compile, install and run absolutely anything you want on a non-rooted Android phone with a locked bootloader (within the constraints of the security system, which is, of course, A Good Thing).

and a 5g radiotelephony MODEM.