@@ -8,7 +8,7 @@ Clause-②: no (a lint verdict widens its refusals; no published payload gains a
 
 <!-- adr-0087: not-required (no-migration-prescription) a refusal of a grouping TARGET at authoring time: a dataset dimensions entry whose field resolves to a declared structured-JSON field (json, composite, repeater, record, location, address, vector) or multi-value field (multiselect, checkboxes, tags, or a select, radio, lookup, user, file or image declared multiple: true). It is the authoring leg of the analytics door that already refuses every query grouping by such a column with 400 INVALID_FIELD, and that door's own changeset declared this category for this surface. No authorable key, spelling, export or stored shape moves: DatasetSchema keeps parsing every dimension, no stored row is read or rewritten, and which scalar part of a document, or which member of a list, an author meant to group on is not something a ledger entry can rewrite. The other categories are closed on facts: the package publishes (not unpublished); no ADR-0087 id covers a grouping target, and dataset-measure-aggregate-field-type-refused says in its own reason that a field used as a DIMENSION is untouched (not already-registered); and the change is a rule verdict, not a declaration (not runtime-interface-only or type-surface-only). -->
 
-**BREAKING**: metadata that passed `os validate`, `os build` and `os lint` can now fail, and so can a runtime dataset save (Studio, REST `/meta`, MCP), which runs the same rule. A dataset dimension is a group key, and the analytics door refuses a query that groups by a JSON-stored column with `400 INVALID_FIELD` before any SQL is built, so such a dimension could be declared but never served. The new rule `dimension-json-stored-field-refused` (gating, `error`) refuses it where the author writes it. It ships as `minor` under the launch-window convention for accept-set narrowings. No export is removed; the `rule` member of `DatasetMeasureAggregateFinding` gains the new id beside `measure-aggregate-field-type-refused`.
+**BREAKING**: metadata that passed `os validate`, `os build` and `os lint` can now fail, and so can a runtime dataset save (Studio, REST `/meta`, MCP), which runs the same rule. A dataset dimension is a group key, and the analytics door refuses a query that groups by a JSON-stored column with `400 INVALID_FIELD` before any SQL is built, so such a dimension could be declared but never served. The new rule `dimension-json-stored-field-refused` (gating, `error`) refuses it where the author writes it. It ships as `minor` under the launch-window convention for accept-set narrowings. No export is removed. The package entry exports the new id as `DIMENSION_JSON_STORED_FIELD_REFUSED`, beside `MEASURE_AGGREGATE_FIELD_TYPE_REFUSED`, and the `rule` member of `DatasetMeasureAggregateFinding` gains it.
 
 **What is refused.** A dimension whose `field` resolves, on the dataset's object or across its join chain, to a field declared with a structured-JSON type (`json`, `composite`, `repeater`, `record`, `location`, `address`, `vector`) or a multi-value declaration (`multiselect`, `checkboxes`, `tags`, or a `select`, `radio`, `lookup`, `user`, `file` or `image` declared `multiple: true`). The two classes are `@objectstack/spec/data`'s `STRUCTURED_JSON_TYPES` and `isMultiValueField`, the predicates the analytics door reads.
 
 
@@ -59,6 +59,7 @@ export type { WidgetBindingFinding, WidgetBindingSeverity } from './validate-wid
 export {
   validateDatasetMeasureAggregates,
   MEASURE_AGGREGATE_FIELD_TYPE_REFUSED,
+  DIMENSION_JSON_STORED_FIELD_REFUSED,
 } from './validate-dataset-measure-aggregates.js';
 export type { DatasetMeasureAggregateFinding } from './validate-dataset-measure-aggregates.js';