feat: add form and page platform

src/adapters/http/client.js

@@ -4,6 +4,7 @@ import {
   createFailure as failure,
   kindForStatus as statusKind,
   normalizeUnknownFailure,
+  safeValidationIssues,
 } from "../../contracts/errors.js";
 import { mapOperationPayload } from "./resource-mapper.js";
 import { retryDelay, shouldRetry } from "./retry-policy.js";
@@ -415,6 +416,10 @@ async function parseResponse(
 
   const kind = statusKind(response.status);
   const retryAfter = response.headers.get("retry-after");
+  const backendError =
+    envelopeRecord.error && typeof envelopeRecord.error === "object"
+      ? /** @type {Record<string, unknown>} */ (envelopeRecord.error)
+      : {};
   return {
     ok: false,
     error: failure(kind, operation.operationId, attempt, {
@@ -426,6 +431,10 @@ async function parseResponse(
         response.status === 429 && retryAfter
           ? parseRetryAfterHeader(retryAfter)
           : undefined,
+      validationIssues:
+        response.status === 422
+          ? safeValidationIssues(backendError.details)
+          : undefined,
     }),
   };
 }