feat(FormField): signal forms support

[marklagendijk]

Feature Description

The first (experimental) version of Signal Forms will land in Angular 21. This is awesome news, because with Signal Forms, forms finally become fully reactive, functional and composable. I would like to be able to use Signal Forms with Angular Material.

For an outsider, it is impossible to see whether Angular Material support for Signal Forms:

1. Will just work out-of-the-box
2. Will require some small changes in Angular Material
3. Requires a huge amount of work in Angular Material

Use Case

As a developer, I love the improvements that Signal Forms will bring to our code base. I am really looking forward to using them in tandem with Angular Material.

[ruiaraujo012]

I just found a limitation in material MatStep, only AbstractControl can be used in stepControl. So we cannot use signal forms yet here.

[michael-small]

I am also curious for more formal talk on this. That said, there is a list item on the signal forms board about Material support. That is a very living board updated over time (last updated on Oct 24), so I won't quote it directly, but it answers various questions for me: https://github.com/orgs/angular/projects/60/views/1?query=sort%3Aupdated-desc+is%3Aopen&pane=issue&itemId=118043297

[vvolodin]

Is there any official status or timeline for this? I naively thought that version 21 of Angular Material will have support for new features in Angular 21.