Modal dialogs: smoother animations and QR code dialog improvements

[nqst]

Changes:

• Polishes .dialog animations by applying ease-out easing¹, increasing the initial scale², centering transform-origin, and making the closing animation faster than the opening one.
• Adds --panel-size to the QR code dialogs (invites and instant login) so they don't go full-width on desktop.
• Adjusts the copy above the QR codes, making it more clear what happens after scanning.
• Uses text-wrap: balance for that copy.
• Uses a consistent close button for the QR code dialogs (Done instead of [x]).
• Uses explicit transition- properties so they're more maintainable.

---

Before:

qr-before.mp4

After:

qr-after.mp4

---

Before	After

Footnotes

1. https://emilkowal.ski/ui/7-practical-animation-tips#4.-choose-the-right-easing ↩

2. https://emilkowal.ski/ui/7-practical-animation-tips#2.-don’t-animate-from-scale(0) ↩