[imorland]

Fixes #5461 (Flarum 2.0.2 bug when quoting text)
Fixes #5389 ([mentions] Quote button flickers during a mouse selection on touch laptops)

Changes proposed in this pull request:
Keep the quote overlay outside animated posts so highlighting a post cannot move the button away from the selection or a pending tap. Preserve the selection when Quote is pressed, and wait for mouse release on touch-capable devices while retaining touch and keyboard selection. Each regression was run red before its fix.

Reviewers should focus on:

• Native Android/Vanadium and iOS selection controls remain unverified; the existing 70px menu clearance is unchanged.

Screenshot
Touch selection while a post is highlighted — before:

After:

Before recording · After recording

Mouse selection on a touch-capable screen, during the drag — before:

After:

Before recording · After recording

Necessity

• Has the problem that is being solved here been clearly explained?
• If applicable, have various options for solving this problem been considered?
• For core PRs, does this need to be in core, or could it be in an extension?
• Are we willing to maintain this for years / potentially forever?

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Frontend changes: tests are green (run yarn test in js/).
• Frontend changes: tests have been added, or are not appropriate here.
• Backend changes: tests are green (run composer test).
• Backend changes: tests have been added, or are not appropriate here.
• Where applicable, changes are suitable for all supported database drivers (MySQL, MariaDB, PostgreSQL, SQLite).
• Core developer confirmed locally this works as intended.
• The description above is written by me and describes what this pull request actually does.