fix(openapi): add relation x-* hints to output schemas too

[eluhr]

Problem

RelationFieldSchemaDecorator only decorated input schemas with x-collection, x-label-property, x-value-property, x-search-property and x-resource-class.

Resources that declare serialization groups get no plain <Name> schema from API Platform, only the grouped <Name>.jsonld-<group>.read and <Name>-<group>.write variants. A client that builds its forms from the read schema (the Vue admin UI does) therefore never saw the hints, and iri-reference fields rendered as bare string inputs instead of the type-ahead from dmstr/jedison-extender-bundle.

Example before (MenuNode.jsonld-menu_node.read):

"menu": { "type": "string", "format": "iri-reference" }

Change

The decorator now processes output schemas as well; the hints are purely additive metadata and harmless on reads. After this change the same read schema carries "x-collection": "/api/admin/menus" and friends.

Verified on a za7 stack with the admin UI: the menu and parent fields on the MenuNode form show the type-ahead with members of /api/admin/menus / /api/admin/menu_nodes.

Notes

• No test added — the decorator has no test coverage yet; happy to add one if wanted.
• Not changed in this PR: the decorator applies the root class's relation metadata to every embedded definition, so a same-named property on an embedded resource could receive the wrong hints. That pre-existing behaviour is now also reachable through read schemas (which embed more often than input schemas). Did not observe it on the stack I tested, but worth a follow-up.

🤖 Generated with Claude Code

[schmunk42]

Approved — additive metadata, no breaking change.

Follow-ups:

• #11: the decorator applies the root class's relation hints to foreign definitions; this PR widens it to output schemas, so it should be fixed next (including the test offered here).
• dmstr/jedison-extender-bundle#2: link to the related record in read-only state — builds on the hints this PR adds to read schemas, and depends on #11.