E-Mail PDF-Downloads als Binärdaten stabilisieren

KI-AGENT: Attachment-Downloads werden im Backend explizit als Buffer mit Content-Length ausgeliefert und im Frontend aus einem ArrayBuffer als Blob erzeugt, damit PDF-Anhänge unverändert gespeichert werden.

frontend/pages/email/index.vue

@@ -457,13 +457,14 @@ async function downloadAttachment(attachment: NonNullable<EmailMessage["attachme
   actionLoading.value = `attachment-${attachment.id}`
   try {
     const response = await $fetch.raw(`/api/email/attachments/${attachment.id}/download`, {
-      responseType: "blob",
+      responseType: "arrayBuffer",
       credentials: "include",
       headers: {
         ...(useCookie("token").value ? { Authorization: `Bearer ${useCookie("token").value}` } : {}),
       },
     })
-    const blob = response._data as Blob
+    const contentType = response.headers.get("content-type") || attachment.contentType || "application/octet-stream"
+    const blob = new Blob([response._data as ArrayBuffer], { type: contentType })
     const disposition = response.headers.get("content-disposition") || ""
     const dispositionFilename = disposition.match(/filename="([^"]+)"/)?.[1]
     const filename = dispositionFilename || attachment.filename || "anhang"