feat(mcp): Dateien ohne Base64 per HTTP hochladen

- POST /api/mcp/files nimmt multipart/form-data oder Rohdaten mit dem MCP-Token an, Ziel Dokumentenablage oder Eingangsrechnung
- documents.files.upload_url liefert Adresse, Parameter und curl-Beispiele
- Upload einer Eingangsrechnung bereitet nur noch die hochgeladene Datei vor

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/src/mcp/tools/accounting.ts

@@ -29,7 +29,7 @@ import {
     prepareStatementAllocationInput,
     statementAllocationUuidArg,
 } from "../statementAllocations"
-import { McpTool } from "../types"
+import { McpContext, McpTool } from "../types"
 import { outgoingStatusTools } from "./outgoingStatus"
 
 export { prepareStatementAllocationInput } from "../statementAllocations"
@@ -312,6 +312,98 @@ const loadIncomingInvoiceFileDefaults = async (context: { server: any; tenantId:
     }
 }
 
+export type IncomingInvoiceFileUpload = {
+    filename: string
+    buffer: Buffer
+    mimeType: string
+    invoiceId?: number | null
+    invoiceArgs?: Record<string, unknown> | null
+    prepare?: boolean
+}
+
+/** Shared by the Base64 tool and the binary MCP upload endpoint. */
+export async function uploadIncomingInvoiceFile(context: McpContext, upload: IncomingInvoiceFileUpload) {
+    const { filename, buffer, mimeType } = upload
+    const invoiceId = upload.invoiceId || null
+    const invoiceArgs = upload.invoiceArgs || null
+    const shouldPrepare = upload.prepare !== false && !invoiceId && !invoiceArgs
+    if (!buffer.length) throw new Error("Datei ist leer")
+    if (buffer.length > MAX_MCP_UPLOAD_BYTES) throw new Error("Datei ist größer als 20 MB")
+
+    let linkedInvoice: any = null
+
+    if (invoiceId) {
+        const [existing] = await context.server.db
+            .select()
+            .from(incominginvoices)
+            .where(and(eq(incominginvoices.id, invoiceId), eq(incominginvoices.tenant, context.tenantId)))
+            .limit(1)
+
+        if (!existing) throw new Error("Eingangsbeleg nicht gefunden")
+        linkedInvoice = existing
+    } else if (invoiceArgs) {
+        const payload = buildIncomingInvoicePayload(invoiceArgs, context.userId, context.tenantId, true)
+        payload.state = "Entwurf"
+
+        const [createdInvoice] = await context.server.db
+            .insert(incominginvoices)
+            .values(payload as any)
+            .returning()
+
+        linkedInvoice = createdInvoice
+    }
+
+    const defaults = await loadIncomingInvoiceFileDefaults(context)
+    const saved = await saveFile(
+        context.server,
+        context.tenantId,
+        null,
+        {
+            filename,
+            content: buffer,
+            contentType: mimeType,
+        },
+        defaults.folderId,
+        defaults.fileTagId,
+        {
+            incominginvoice: linkedInvoice?.id || null,
+            createdBy: context.userId,
+            updatedBy: context.userId,
+            updatedAt: new Date(),
+        }
+    )
+
+    if (!saved) throw new Error("Datei konnte nicht gespeichert werden")
+
+    if (shouldPrepare) {
+        // Only the uploaded file; other open invoice files stay for an explicit preparation run.
+        await context.server.services.prepareIncomingInvoices.run(context.tenantId, { fileIds: [saved.id] })
+    }
+
+    const [file] = await context.server.db
+        .select()
+        .from(files)
+        .where(and(eq(files.id, saved.id), eq(files.tenant, context.tenantId)))
+        .limit(1)
+
+    if (file?.incominginvoice && !linkedInvoice) {
+        const [preparedInvoice] = await context.server.db
+            .select()
+            .from(incominginvoices)
+            .where(and(eq(incominginvoices.id, file.incominginvoice), eq(incominginvoices.tenant, context.tenantId)))
+            .limit(1)
+
+        linkedInvoice = preparedInvoice || null
+    }
+
+    return {
+        file,
+        invoice: linkedInvoice,
+        validation: linkedInvoice ? validateIncomingInvoiceData(linkedInvoice as Record<string, any>) : null,
+        prepared: Boolean(shouldPrepare && linkedInvoice),
+    }
+}
+
 const buildIncomingInvoicePayload = (
     args: Record<string, unknown>,
     userId: string,
@@ -1014,7 +1106,7 @@ export const accountingTools: McpTool[] = [
     {
         name: "accounting.incoming_invoices.files.upload",
         title: "Datei für Eingangsbeleg hochladen",
-        description: "Lädt eine PDF- oder Bilddatei als Base64 hoch, verknüpft sie optional mit einem Eingangsbeleg oder stößt die automatische Vorbereitung an.",
+        description: "Lädt eine PDF- oder Bilddatei als Base64 hoch, verknüpft sie optional mit einem Eingangsbeleg oder stößt die automatische Vorbereitung dieser Datei an. Mit Dateizugriff besser ohne Base64 über die Adresse aus documents.files.upload_url (target=incoming_invoice) hochladen.",
         requiredPermissions: ["accounting.incoming_invoices.write"],
         inputSchema: {
             type: "object",
@@ -1050,83 +1142,14 @@ export const accountingTools: McpTool[] = [
             const filename = stringArg(args, "filename")
             if (!filename) throw new Error("filename ist erforderlich")
 
-            const buffer = base64BufferArg(args, "contentBase64")
-            const mimeType = stringArg(args, "mimeType") || "application/octet-stream"
-            const invoiceId = numberArg(args, "invoiceId")
-            const invoiceArgs = optionalObjectArg(args, "invoice") as Record<string, unknown> | null
-            const shouldPrepare = args.prepare !== false && !invoiceId && !invoiceArgs
-
-            let linkedInvoice: any = null
-
-            if (invoiceId) {
-                const [existing] = await context.server.db
-                    .select()
-                    .from(incominginvoices)
-                    .where(and(eq(incominginvoices.id, invoiceId), eq(incominginvoices.tenant, context.tenantId)))
-                    .limit(1)
-
-                if (!existing) throw new Error("Eingangsbeleg nicht gefunden")
-                linkedInvoice = existing
-            } else if (invoiceArgs) {
-                const payload = buildIncomingInvoicePayload(invoiceArgs, context.userId, context.tenantId, true)
-                payload.state = "Entwurf"
-
-                const [createdInvoice] = await context.server.db
-                    .insert(incominginvoices)
-                    .values(payload as any)
-                    .returning()
-
-                linkedInvoice = createdInvoice
-            }
-
-            const defaults = await loadIncomingInvoiceFileDefaults(context)
-            const saved = await saveFile(
-                context.server,
-                context.tenantId,
-                null,
-                {
-                    filename,
-                    content: buffer,
-                    contentType: mimeType,
-                },
-                defaults.folderId,
-                defaults.fileTagId,
-                {
-                    incominginvoice: linkedInvoice?.id || null,
-                    createdBy: context.userId,
-                    updatedBy: context.userId,
-                    updatedAt: new Date(),
-                }
-            )
-
-            if (!saved) throw new Error("Datei konnte nicht gespeichert werden")
-
-            if (shouldPrepare) {
-                await context.server.services.prepareIncomingInvoices.run(context.tenantId)
-            }
-
-            const [file] = await context.server.db
-                .select()
-                .from(files)
-                .where(and(eq(files.id, saved.id), eq(files.tenant, context.tenantId)))
-                .limit(1)
-
-            if (file?.incominginvoice && !linkedInvoice) {
-                const [preparedInvoice] = await context.server.db
-                    .select()
-                    .from(incominginvoices)
-                    .where(and(eq(incominginvoices.id, file.incominginvoice), eq(incominginvoices.tenant, context.tenantId)))
-                    .limit(1)
-
-                linkedInvoice = preparedInvoice || null
-            }
-
-            return {
-                file,
-                invoice: linkedInvoice,
-                validation: linkedInvoice ? validateIncomingInvoiceData(linkedInvoice as Record<string, any>) : null,
-                prepared: Boolean(shouldPrepare && linkedInvoice),
-            }
+            return uploadIncomingInvoiceFile(context, {
+                filename,
+                buffer: base64BufferArg(args, "contentBase64"),
+                mimeType: stringArg(args, "mimeType") || "application/octet-stream",
+                invoiceId: numberArg(args, "invoiceId"),
+                invoiceArgs: optionalObjectArg(args, "invoice") as Record<string, unknown> | null,
+                prepare: args.prepare !== false,
+            })
         },
     },
     {