fix: make join review read only

harness/.pi/extensions/gate/builders.js

@@ -177,6 +177,28 @@ function buildSchemaLinkingRequest({ id, phase, title, tables }) {
   };
 }
 
+// Build a blocking, read-only join review. The reviewer can accept the complete
+// proposal or use Other to request a textual correction; individual joins are
+// deliberately not selectable because omitting one could create a Cartesian product.
+function buildJoinReviewRequest({ id, phase, title, options }) {
+  requireString(title, "title", "join-review");
+  const opts = requireArray(options, "options", "join-review");
+  if (opts.length === 0) {
+    throw new Error("builders: join-review requires at least one option");
+  }
+  return {
+    type: "ui_request",
+    id,
+    phase,
+    schema_version: SCHEMA_VERSION,
+    widget: "join-review",
+    title,
+    options: [...opts],
+    confirm_label: "Continue",
+    reserved: RESERVED,
+  };
+}
+
 // Attach a child-widget spec to an option (linkage, §4.2). Returns the option.
 function withChildLinkage(option, widgetSpec) {
   option.opens = widgetSpec;
@@ -190,6 +212,7 @@ module.exports = {
   buildInfoRequest,
   buildFreetextRequest,
   buildSchemaLinkingRequest,
+  buildJoinReviewRequest,
   withChildLinkage,
   SCHEMA_VERSION,
   RESERVED,