Intent to Ship: CSS Typed Arithmetic

[Sajid Anwar]

As of Firefox 158, I intend to enable CSS Typed Arithmetic (unit algebra) by default on all platforms. This capability has been developed behind the layout.css.calc-typed-arithmetic.enabled preference, and has been enabled in Nightly since Firefox 155. These features have been shipped in other browsers since Chrome 140 and Safari 26.

Bugs:
- Bug 1827404 - [css-values-4] Support division/multiplication/subtraction of mixed units in math functions like calc() and sign() (removal of unit) - Main bug.
- Bug 2067411 - [css-typed-arithmetic] Set layout.css.calc-typed-arithmetic.enabled for release - Bug to launch feature.

Standard:
https://drafts.csswg.org/css-values-4/#calc-type-checking

Intent to Prototype Thread:
https://groups.google.com/a/mozilla.org/g/dev-platform/c/iG6FI5DosEg/m/ay72WDXPAQAJ