Builds a changeset for a resource when a changeset callback is configured.

Returns explicit form fields, or inferred Ecto schema fields when no form DSL was declared.

Builds an empty record for a resource form.

Resolves the concrete resource metadata used for form fields, records, and changesets.

Local sessions render portable surface maps that lack the repo, changeset callback, and schema needed by forms, so resolve the real metadata from the local admin's declared resources. Returns nil when the resource is not form-capable.