fix(sdk): wrap thrown error bodies in Error

SDK throwOnError paths now convert structured response bodies into real Error instances while preserving the original body and status in cause.

packages/sdk/js/src/v2/client.ts

@@ -3,6 +3,7 @@ export * from "./gen/types.gen.js"
 import { createClient } from "./gen/client/client.gen.js"
 import { type Config } from "./gen/client/types.gen.js"
 import { OpencodeClient } from "./gen/sdk.gen.js"
+import { wrapClientError } from "../error-interceptor.js"
 export { type Config as OpencodeClientConfig, OpencodeClient }
 
 function pick(value: string | null, fallback?: string, encode?: (value: string) => string) {
@@ -84,24 +85,6 @@ export function createOpencodeClient(config?: Config & { directory?: string; exp
 
     return response
   })
-  // The generated client falls back to throwing a literal `{}` when the server
-  // responds with an empty / unparseable error body, which surfaces as a bare
-  // `{}` in TUI / CLI error output. Wrap ONLY that case in a real Error so
-  // downstream formatters get a useful message — but pass through any parsed
-  // JSON error body unchanged so existing consumers can still inspect fields.
-  client.interceptors.error.use((error, response, request) => {
-    const isEmpty =
-      error === undefined ||
-      error === null ||
-      error === "" ||
-      (typeof error === "object" && !(error instanceof Error) && Object.keys(error).length === 0)
-    if (!isEmpty) return error
-    const method = request?.method ?? "?"
-    const url = request?.url ?? "?"
-    if (!response) return new Error(`opencode server ${method} ${url}: network error (no response)`)
-    const status = response.status
-    const statusText = response.statusText ? " " + response.statusText : ""
-    return new Error(`opencode server ${method} ${url} → ${status}${statusText}: (empty response body)`)
-  })
+  client.interceptors.error.use(wrapClientError)
   return new OpencodeClient({ client })
 }