feat: store workspace preferences and drafts locally

frontend/src/api/client.ts

@@ -12,23 +12,36 @@ export class ApiError extends Error {
   }
 }
 
-export async function apiFetch<T>(path: string, init?: RequestInit): Promise<T> {
-  // Only declare a JSON content-type when we actually send a body. Body-less
-  // POSTs (resume, close) would otherwise make Fastify reject the empty body
-  // with FST_ERR_CTP_EMPTY_JSON_BODY (400).
-  const headers: Record<string, string> = {
-    ...(init?.headers as Record<string, string> | undefined),
-  };
-  if (init?.body != null && !("content-type" in headers) && !("Content-Type" in headers)) {
-    headers["content-type"] = "application/json";
+function requestHeaders(init: RequestInit | undefined): Headers {
+  const headers = new Headers(init?.headers);
+  // Fetch supplies the multipart boundary for FormData. Declaring JSON here
+  // would prevent Fastify from parsing an imported workspace bundle.
+  if (
+    init?.body != null
+    && !(typeof FormData !== "undefined" && init.body instanceof FormData)
+    && !headers.has("content-type")
+  ) {
+    headers.set("content-type", "application/json");
   }
-  const res = await fetch(joinBackendPath(BASE, path), { ...init, headers });
+  return headers;
+}
+
+async function request(path: string, init?: RequestInit): Promise<Response> {
+  const res = await fetch(joinBackendPath(BASE, path), { ...init, headers: requestHeaders(init) });
   if (!res.ok) {
     const bodyText = await res.text().catch(() => "");
     let payload: unknown;
     try { payload = bodyText ? JSON.parse(bodyText) : undefined; } catch { payload = undefined; }
     throw new ApiError(res.status, bodyText, payload);
   }
+  return res;
+}
+
+export async function apiFetch<T>(path: string, init?: RequestInit): Promise<T> {
+  // Only declare a JSON content-type when we actually send a body. Body-less
+  // POSTs (resume, close) would otherwise make Fastify reject the empty body
+  // with FST_ERR_CTP_EMPTY_JSON_BODY (400).
+  const res = await request(path, init);
   if (res.status === 204) return undefined as T;
   // Accepted fire-and-forget endpoints may legitimately return 202 with no
   // representation. Keep apiFetch useful for both 202 and 204 contracts.
@@ -36,4 +49,9 @@ export async function apiFetch<T>(path: string, init?: RequestInit): Promise<T>
   return body ? (JSON.parse(body) as T) : (undefined as T);
 }
 
+/** Download registry bundles without attempting to parse their ZIP body as JSON. */
+export async function apiFetchBlob(path: string, init?: RequestInit): Promise<Blob> {
+  return (await request(path, init)).blob();
+}
+
 export { BASE };