fix case where opencode wasn't retrying

packages/opencode/src/session/message-v2.ts

@@ -9,6 +9,8 @@ import { Snapshot } from "@/snapshot"
 import { fn } from "@/util/fn"
 import { Storage } from "@/storage/storage"
 import { ProviderTransform } from "@/provider/transform"
+import { STATUS_CODES } from "http"
+import { iife } from "@/util/iife"
 
 export namespace MessageV2 {
   export const OutputLengthError = NamedError.create("MessageOutputLengthError", z.object({}))
@@ -739,7 +741,28 @@ export namespace MessageV2 {
           { cause: e },
         ).toObject()
       case APICallError.isInstance(e):
-        const message = ProviderTransform.error(ctx.providerID, e)
+        const message = iife(() => {
+          let msg = e.message
+          const transformed = ProviderTransform.error(ctx.providerID, e)
+          if (transformed !== msg) {
+            return transformed
+          }
+          if (!e.responseBody || (e.statusCode && msg !== STATUS_CODES[e.statusCode])) {
+            return msg
+          }
+
+          try {
+            const body = JSON.parse(e.responseBody)
+            // try to extract common error message fields
+            const errMsg = body.message || body.error
+            if (errMsg && typeof errMsg === "string") {
+              return `${msg}: ${errMsg}`
+            }
+          } catch {}
+
+          return `${msg}: ${e.responseBody}`
+        })
+
         return new MessageV2.APIError(
           {
             message,