support .ipa and .app files
With the EU Digital Markets Act, it is looking like iOS will be forced to open up to third party app stores. There are already a couple of free software app store like things like AppFair, AltStore, and Cydia. F-Droid provides all the tooling to run such a thing, we just need to support the native file formats .ipa and .app. These files have an Application ID and Version Code like Android APKs, so they should fit into our existing structures for apps. Plus index-v2 is flexible enough to handle any new metadata structures that might be needed (e.g. iOS permissions, etc.). Even though macOS and iOS are non-free platforms, I think it makes sense for F-Droid to merge support for them because we can all share the free software infrastructure.
@n8fr8 @threeletteracronym @marcprux could you provide us with free software .ipa and/or .app files to develop and test with? Ideally, they'd be as small as possible, so we can commit them to our git. Like we have some Android .apk files that are 15k.