Server: Infer property type from discriminator/oneOf in getProperty

[lehni]

Written by Claude.

Problem

Model.getProperty(name) resolves $ref schemas but doesn't infer a top-level type when the resolved definition uses JSON Schema constructs that imply a type without stating one explicitly. Concretely, deleting a row whose model has an asset path like content.article.items[**].file blows up at QueryBuilder.loadDataPath():

QueryBuilderError: Unable to load full data-path 'content.article.items[**].file' (Unmatched: 'article/items/**/file').

The check in loadDataPath() requires property.type to be 'object' or 'array' (or a wildcard) to traverse a nested data path. When content is defined as:

{
  $ref: '#StoryContent',
  definitions: {
    '#StoryContent': {
      discriminator: { propertyName: 'type' },
      oneOf: [/* { type: 'object', ... }, ... */]
    }
  }
}

getProperty() resolves the $ref but the merged property has discriminator + oneOf and no type — so the check fails.

Fix

Extend getProperty() to fill in the missing type when it can be inferred unambiguously:

• A discriminator implies type: 'object' (per JSON Schema / OpenAPI semantics).
• A homogeneous oneOf / anyOf / allOf adopts its branches' shared type.

This is additive — existing properties with explicit type are unchanged. Any caller that previously branched on property.type === undefined for these schemas will now see the inferred type, which is what they would have expected if the schema author had spelled it out.

Test plan

• pnpm vitest run packages/server/src/models/Model.test.js — 6 new unit tests cover explicit type, discriminator-on-$ref, homogeneous oneOf/anyOf, mixed oneOf, missing property
• CI green (lint + unit + e2e)