The `runes.prefer` docs example uses an npm name that `mergePlugins` never matches

Found by WORK-634 (#695).

site/content/extend/plugin-authoring/authoring.md ("Name Collision Resolution") shows:

main View source

Relationships

ID:SPEC-153Status:implemented

Delivering composed runes

ID:WORK-634Status:done

A project defines its own composed runes in runes.dir

Priority:highComplexity:complexMilestone:v0.41.0

main current confirmed

claude/post-v0.38-roadmap-jb7pie confirmed claude/v041-plan-runes-keep-content confirmed main confirmed

Steps to Reproduce

Configure two plugins that both define hero, and copy the docs example: "runes": { "prefer": { "hero": "@my-org/custom" } }.
Build a page using {% hero %}.

Expected

The documented example works when copied.

Actual

The preference is ignored with no warning. The collision resolves by the default rule.

Fix

Either:

correct the examples to the short name, and state which name is meant; or
accept the npm name as well in mergePlugins.

The second is friendlier, since the npm name is the one a user sees in refrakt.config.json's plugins list. Either way, an unknown prefer value should warn rather than be ignored.