refactor: clean upload pipeline and restore draco delivery

app/api/upload/drive/route.ts

@@ -10,6 +10,7 @@ import {
 import { acquireUploadLock, releaseUploadLock } from '@/lib/upload-lock'
 import { parseDriveRequestBody } from '@/lib/upload-request'
 import { getErrorMessage } from '@/lib/guards'
+import type { DriveAction } from '@/lib/types'
 
 export const runtime = 'nodejs'
 export const dynamic = 'force-dynamic'
@@ -27,7 +28,7 @@ export async function POST(req: NextRequest) {
 
   let folderName: string
   let parsedFiles: Awaited<ReturnType<typeof readStagedOriginalFiles>>['files']
-  let action: 'new' | 'replace'
+  let action: DriveAction
 
   try {
     const body: unknown = await req.json()