fix(richtext-lexical): coerce integer upload and relationship IDs to number during HTML conversion

[anaghroy]

What?

We are modifying the Lexical HTML converter ($convertUploadElement and $relationshipElementToNode) so that when it extracts integer IDs from the data-lexical-[type]-id HTML attribute, it correctly casts them into Number types instead of leaving them as strings.

Why?

When a Payload project is configured to use integer IDs for a collection (e.g. media), saving a Rich Text field containing Upload or Relationship nodes can fail validation. Because the Lexical DOM parser natively grabs HTML attributes as strings, it was passing a string (e.g. "2") into $createNode instead of the integer 2. This causes Payload's internal lifecycle hooks to reject the payload entirely with a ValidationError.

How?

Inside conversions.ts and RelationshipNode.tsx, we added a strict type-coercion check:

if (String(Number(id)) === id) {
  id = Number(id)
}

Screenshots

Closes #17344