Photo picker for stories cannot pick new photos

[WhyNotHugo]

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• This isn't a feature request or a discussion topic

Bug description

It seems Signal uses its own custom photo picker instead of the iOS one. The problem is that a custom photo picker can only enumerate photos for which I’ve granted Signal access. So, in my case, I only see a single one.

The only workaround is to go into iOS settings > Signals > Photos > Edit Selected Photos, pick the new photo I want to upload there (eg: grant Signal access to it), then jump back into Signal and redo the above steps, and the photo is pickable.

Clearly the workaround is a huge pain, and I suspect most iOS users don't even know how to dig into settings to fix this. The photo also has to be picked twice: once in settings and once again in signal.

Steps to reproduce

Many months ago, I used the "share photo" option on a conversation on Signal. At the time, I picked a single photo to share (the one I was about to send). This is relevant context; the first time you use Signal's photo picker it will work, but only the first time.

• Click on the stories tab
• Tap on the button to upload a new one
• Only the photo to which Signal has already been granted access is show.

Actual result

I can only pick the photo to which Signal has already been granted access.

Expected result

I should be able to pick another, different, photo.

Device info

Device: iPhone 11 Pro

iOS version: 16.0

Signal version: 5.59.10

Possible solution

The obvious solution here is: simply use iOS image picker. The current approach won't work because it only lists photos to which Signal has been granted access (but Signal has no shortcut to change this without digging into settings).

I'm not entirely sure of the exact API (I'm an iOS user, not developer), but apps like Fastmail get this right: when I want to attach a photo to an email, it pops up iOS's photo picker, which allows me to pick any photo on my phone.

Alternatives considered

Instagram tries to work around this by showing a link on the photo picker to use the native iOS photo picker to select new photos. With this approach, one can easily grant access to new photos, but when uploading a new story, one has to pick the photo twice, first on the iOS photo picker, and then on Instagram's internal one. I don't know how they consider this good UX.

Additional context

This was originally reported as #5478. However, nobody filed the paperwork in time, and the original issue expired.

Please do keep in mind that this kind of stale bots are counterproductive; they just add more churn and don't really fix anything.