Lexical default HTML converter for Relationship Node not working

Describe the Bug

I'm using convertLexicalToHTMLAsync to generate HTML, BUT I found the Relationship Node being converted to <span>unknown node</span>.

After checking, I found that there is no Relationship converter. From my understanding, all existing converters are listed here.

Can you help provide an official convert for the Relationship node? Thanks!

Link to the code that reproduces this issue

N/A

Reproduction Steps

convert code:

const result = await convertLexicalToHTMLAsync({
  data,
  populate: await getPayloadPopulateFn({
    payload: req.payload,
    depth: 1,
    currentDepth: 0,
  }),
})

current: the Relationship node being converted to <span>unknown node</span>
expected: the Relationship node can be converted correctly

Which area(s) are affected? (Select all that apply)

plugin: richtext-lexical

Environment Info

Binaries:
  Node: 20.19.5
  npm: 10.8.2
  Yarn: N/A
  pnpm: 10.22.0
Relevant Packages:
  payload: 3.56.0
  next: 15.4.4
  @payloadcms/db-mongodb: 3.56.0
  @payloadcms/email-nodemailer: 3.56.0
  @payloadcms/graphql: 3.56.0
  @payloadcms/next/utilities: 3.56.0
  @payloadcms/payload-cloud: 3.56.0
  @payloadcms/plugin-cloud-storage: 3.56.0
  @payloadcms/richtext-lexical: 3.56.0
  @payloadcms/storage-gcs: 3.56.0
  @payloadcms/translations: 3.56.0
  @payloadcms/ui/shared: 3.56.0
  react: 19.1.0
  react-dom: 19.1.0
Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 25.1.0: Mon Oct 20 19:33:36 PDT 2025; root:xnu-12377.41.6~2/RELEASE_ARM64_T6030
  Available memory (MB): 36864
  Available CPU cores: 12

Start with the linked packages/richtext-lexical/features/converters/lexicalToHtml/async/defaultConverters.ts and trace how convertLexicalToHTMLAsync selects converters. Confirm the Relationship node is handled by an official converter and no longer renders as unknown node, then verify the existing rich-text conversion coverage.