[Bug] Video processing fails with "detached ArrayBuffer" error

[LucaOlovrap]

Description

In the self-hosted version (v0.4.3), video processing fails immediately after the upload reaches 100%. The application fails to generate or rename the result.mp4 file in the S3 bucket (MinIO), leading to a 404 error in the browser and a "MEDIA_ELEMENT_ERROR: Format error" in the player.

Crucial Manual Test:
I confirmed that if I manually rename the file raw-upload.mp4 to result.mp4 inside the MinIO bucket, the video player starts working perfectly. This proves that the infrastructure (S3, Proxy, DNS) is correct, but the internal worker/process responsible for transcoding or renaming the file is crashing.

Reproduction

1. Deploy Cap v0.4.3 using Docker Compose with MinIO.
2. Set up a reverse proxy (like Caddy) for video.example.com and files.example.com.
3. Upload a video through the dashboard.
4. Observe the upload finishing, but the video remaining unplayable (404 on result.mp4).
5. Check container logs to find the detached ArrayBuffer error.

Additional Context

• Cap version: v0.4.3 (Image: ghcr.io/capsoftware/cap-web:latest)
• Operating system, version: Linux (Ubuntu 24.04)
• Device (optional): Server Deployment

Error Logs:

[local world] Queue operation failed: TypeError: fetch failed
    at async (.next/server/chunks/2242.js:30:10424) {
  [cause]: TypeError: Cannot perform ArrayBuffer.prototype.slice on a detached ArrayBuffer
      at ArrayBuffer.slice (<anonymous>)
}

Docker Compose Configuration:

services:
  cap-web:
    image: ghcr.io/capsoftware/cap-web:latest
    container_name: cap-web
    restart: unless-stopped
    environment:
      NEXTAUTH_URL: [https://video.example.com](https://video.example.com)
      WEB_URL: [https://video.example.com](https://video.example.com)
      NEXTAUTH_SECRET: "REDACTED"
      DATABASE_ENCRYPTION_KEY: "REDACTED"
      DATABASE_URL: mysql://capuser:password@db:3306/capdb
      CAP_AWS_ACCESS_KEY: minioadmin
      CAP_AWS_SECRET_KEY: "password"
      CAP_AWS_BUCKET: cap-uploads
      CAP_AWS_REGION: us-east-1
      S3_INTERNAL_ENDPOINT: http://minio:9000
      S3_PUBLIC_ENDPOINT: [https://files.example.com](https://files.example.com)
      S3_FORCE_PATH_STYLE: "true"

  db:
    image: mysql:8.0
    container_name: cap-db
    environment:
      MYSQL_ROOT_PASSWORD: "password"
      MYSQL_DATABASE: capdb
    volumes:
      - db_data:/var/lib/mysql

  minio:
    image: minio/minio
    container_name: cap-minio
    command: server /data --console-address ":9001"
    environment:
      MINIO_ROOT_USER: minioadmin
      MINIO_ROOT_PASSWORD: "password"
      MINIO_SERVER_URL: "[https://files.example.com](https://files.example.com)"
      MINIO_API_CORS_ALLOW_ORIGIN: "[https://video.example.com](https://video.example.com)"
    volumes:
      - minio_data:/data

volumes:
  db_data:
  minio_data:

Thank you!

[linear]

CAP-618