feat: slot layouts over wrapping operations

[arbrandes]

Description

Adds an ADR documenting the decision to not implement a widget wrapping operation in frontend-base. The legacy @openedx/frontend-plugin-framework provided a Wrap operation, used notably by frontend-plugin-aspects to toggle sidebar visibility. The ADR explains why the existing layout system is the architecturally preferred alternative, and why a wrapping operation is fundamentally at odds with the slot/layout/widget pipeline.

As part of this decision, useWidgets() is enriched with identity-based filtering helpers (byId(), withoutId(), byRole(), withoutRole()). These methods let layouts selectively render widgets without breaking backwards compatibility — the returned array still renders identically when used as-is. Internally, the widget metadata (ID and role) that was previously stripped before reaching layouts is now preserved and exposed through these helpers.

The slot showcase gains a new demo showing widgets.byRole() in action: a layout that toggles between all widgets and only those with a "highlighted" role. Two existing showcase options that were passing JSX elements instead of plain strings are also fixed.

LLM usage notice

Built with assistance from Claude models (mostly Opus 4.6).

[arbrandes]

@jsnwesson and @MaxFrank13, would love your thoughts on this, as I suspect you might actually use FPF's wrap operation.

[holaontiveros]

It makes a lot of sense, I still haven't seen in depth the old system I just check a couple of things on how it worked before so given that many thigns will need to be fully migrated to be compatible with frontend-base maybe we should have some links to some succesful migrations after they start appearing, so everyone can do it easily.

I does look straighforward but depending on how the people look at it some example to wrap their head saround it may be helpful

[arbrandes]

@holaontiveros

maybe we should have some links to some succesful migrations after they start appearing, so everyone can do it easily.

Totally. I originally thought about converting frontend-plugin-aspects itself, but unfortunately it targets slots in frontend-app-authoring, which is the last one on the list to be converted to frontend-base.

We'll figure something out in the docs.