Fix mobile unstyled appearance for clipboard button

[aduth]

🛠 Summary of changes

Fixes a bug where the "Copy" button appears incorrect on the Personal Key confirmation screen at small viewport sizes, regressed in #8307 due to a workaround introduced to resolve an upstream issue with button display at small viewport sizes.

The workaround caused all buttons to appear as display: block, but since an unstyled button is expected to appear as display: inline (source), these should be excluded from the workaround.

📜 Testing Plan

1. Go to http://localhost:3000
2. Sign in or create an account
3. Go to http://localhost:3000/verify
4. Complete identity verification up to personal key screen
5. If on desktop, use devtools screen size emulator to emulate a mobile phone viewport width
6. Observe that "Copy" link appears inline

👀 Screenshots

Before	After