refactor: strengthen upload boundary types

app/api/upload/drive/route.ts

@@ -8,6 +8,7 @@ import {
   findNextVersion,
 } from '@/lib/nextcloud'
 import { acquireUploadLock, releaseUploadLock } from '@/lib/upload-lock'
+import { parseDriveRequestBody } from '@/lib/upload-request'
 
 export const runtime = 'nodejs'
 export const dynamic = 'force-dynamic'
@@ -45,15 +46,13 @@ export async function POST(req: NextRequest) {
   // --- Parse staging request ---
   let folderName: string
   let parsedFiles: Awaited<ReturnType<typeof readStagedOriginalFiles>>['files']
-  let action: string
+  let action: 'new' | 'replace'
 
   try {
-    const body = await req.json()
-    const stagingId = body.stagingId
-    if (!stagingId || typeof stagingId !== 'string') {
-      throw new Error('stagingId manquant')
-    }
-    action = typeof body.action === 'string' ? body.action.trim() || 'new' : 'new'
+    const body: unknown = await req.json()
+    const parsedBody = parseDriveRequestBody(body)
+    action = parsedBody.action
+    const stagingId = parsedBody.stagingId
     const staged = await readStagedOriginalFiles(stagingId)
     folderName = staged.folderName
     parsedFiles = staged.files