fix: tolerate blank creative job requests

web/lib/api.ts

@@ -378,9 +378,18 @@ export async function generateCreativeCopy(body: {
 }
 
 export async function createCreativeImageJob(file?: File | null): Promise<Job> {
-  const fd = new FormData()
-  if (file) fd.append("file", file)
-  const res = await fetch(`${API_BASE}/creative/jobs/image`, { method: "POST", body: fd })
+  const init: RequestInit = file
+    ? (() => {
+        const fd = new FormData()
+        fd.append("file", file)
+        return { method: "POST", body: fd }
+      })()
+    : {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: "{}",
+      }
+  const res = await fetch(`${API_BASE}/creative/jobs/image`, init)
   if (!res.ok) {
     const txt = await res.text().catch(() => "")
     throw apiError("createCreativeImageJob", res.status, txt)