fix(database): detect wrapped Relation field types

[JohnChantz]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

The PR fulfills these requirements:

• It's submitted to the master branch
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx, where "xxx" is the issue number)

Other information:

In Database → Models → schema fields, array relations often showed as String instead of Relation, with no related-model picker. Saving that view would persist { type: "String" } and drop the relation.

Scalar relations ({ type: "Relation", model: "User" }) already worked. The miss was Conduit’s wrapped array form, common in production schemas:

{
  "type": [{ "type": "Relation", "model": "Team" }]
}

The editor now unwraps that shape (and { type: ["Relation"], model }) and treats a string model as Relation. The document form uses the same parser, so those fields get the relation picker instead of a text input. Saving still writes the canonical [ { type: "Relation", model } ] array.

Test plan

• pnpm test:schema-fields — 9 cases covering scalar Relation, both array encodings, String arrays, Group, and missing type
• Open a model whose fields use { type: [{ type: "Relation", model }] } (e.g. sharedWithTeams) and confirm type is Relation, model picker is filled, array is on
• Confirm a scalar Relation field is unchanged
• Confirm { type: ["String"] } stays String with array on
• In the data explorer, those relation fields use the document picker, not a plain text input

Could not exercise the UI locally in this pass (no running admin server).