I've been working on a small iOS app, intended as a gift to some family members. To my dismay, I'm finding a lot of barriers to attempting to deploy the app. It largely revolves around signing the app to actually be runnable on devices in question, which aren't rooted/jailbroken, and don't have any other particular reason to be.
From my research thus far, I've gathered that the free provisioning Apple provides for can only produce certificates valid for 7 days. Since the app depends on persisted, user-generated data, even were the recipients willing to reinstall every week this would still be a non-starter. On top of that, the Apple ID associated with said devices is a very old ID that a known issue has Xcode being unable to verify the ID. So the free provisioning is not an option.
To an extent I'm balking at the Apple Developer Program subscription fees. However, I'm wondering whether that would even fix the issue? Is there a method within the (paid) Apple Developer Program to deploy directly to local iOS devices, for long-term use, without publishing to the App Store or going through any sort of approval process with Apple? Is this supported by the Ad Hoc deployment provisions of the program? And in that case, would there be a way for an installation of the app to be able to survive later ceasing to renew the Developer Program subscription?
I'd really appreciate if there were a way to deploy as such for free that can work with a legacy Apple ID, but I've already gotten the impression that's not the case - correct me if I'm wrong.