E-Mail Anhang-Downloads stabilisieren

KI-AGENT: Lädt Anhänge nun authentifiziert als Blob herunter und macht die Backend-Zuordnung von Anhängen zur Originalmail robuster, inklusive Positions-Fallback.

backend/src/modules/email/email.sync.service.ts

@@ -1,5 +1,5 @@
 import { FastifyInstance } from "fastify"
-import { and, desc, eq } from "drizzle-orm"
+import { and, asc, desc, eq } from "drizzle-orm"
 import { ImapFlow } from "imapflow"
 import { simpleParser } from "mailparser"
 
@@ -625,6 +625,13 @@ export function emailSyncService(server: FastifyInstance) {
         const row = rows[0]
         if (!row) return null
 
+        const messageAttachments = await server.db
+            .select()
+            .from(emailAttachments)
+            .where(eq(emailAttachments.messageId, row.message.id))
+            .orderBy(asc(emailAttachments.createdAt), asc(emailAttachments.id))
+        const attachmentIndex = messageAttachments.findIndex((attachment) => attachment.id === attachmentId)
+
         const account = await getAccount(tenantId, userId, row.message.accountId)
         if (!account) {
             throw new Error("E-Mail Konto nicht gefunden")
@@ -644,7 +651,7 @@ export function emailSyncService(server: FastifyInstance) {
                     if (!fetched.source) break
 
                     const parsed = await simpleParser(fetched.source)
-                    const attachment = parsed.attachments.find((item) =>
+                    const matchedAttachment = parsed.attachments.find((item) =>
                         (row.attachment.checksum && item.checksum === row.attachment.checksum)
                         || (
                             item.filename === row.attachment.filename
@@ -652,6 +659,9 @@ export function emailSyncService(server: FastifyInstance) {
                             && Number(item.size || 0) === Number(row.attachment.size || 0)
                         )
                     )
+                    const attachment = matchedAttachment
+                        || parsed.attachments[attachmentIndex]
+                        || (parsed.attachments.length === 1 ? parsed.attachments[0] : null)
 
                     if (!attachment) break