Unofficial Homestuck Collection does not support clipboard-read and clipboard-write attributes

[EtchJetty]

It is impossible to give clipboard access to iframes.
According to #w3c/webappsec-permissions-policy#322 (comment) and this bug report, chrome versions 81-85 had broken iframe clipboard permissions. The feature policies clipboard-write and clipboard-allow were created to solve this issue, but the UHC seems to not recognize them. (The bug was fixed in Chrome 85, which was first used in Electron 10.0, a version newer than the UHC's Electron.)

To Reproduce
Steps to reproduce the behavior:

1. Make an iframe which includes a clipboard link. https://smart-flicker-baroness.glitch.me/ includes one.
2. The same iframe that works in modern browsers (<iframe ... allow="clipboard-read; clipboard-write;">) will fail in the UHC2.

Expected behavior
The parent window (the UHC) should recognize the policies and change behavior accordingly; this does not happen.

Screenshots

Desktop (please complete the following information):

• Application version: v2.0.5
• Asset pack version: v2
• OS: MacBook Air (M1, 2020), running macOS Monterey 12.1 (21C52)

Additional context
iframe is meant to be used for the "share" button in this project. The iframe is in use here, with security policies functioning as expected.

Here is a link to a mod file which includes the iframe within its template.

[GiovanH]

Test case https://mspfa.com/?s=45209&p=1

https://bugs.chromium.org/p/chromium/issues/detail?id=1074489
w3c/webappsec-permissions-policy#322 (comment)
HearthSim/twitch-hdt-frontend#50 (comment) also potential here