Add server identity headers to remote uploads

[Copilot]

Remote upload providers need enough context to attribute uploads without exposing sensitive request data. This adds opt-out server identity headers for screenshot and video uploads, including the FiveM server name, resource name, and destination host.

• Upload identity headers

  • Adds default headers to outbound screenshot and video upload requests:
    • User-Agent
    • X-Screencapture-Server-Name
    • X-Screencapture-Upload-Host
    • X-Screencapture-Resource
  • Extracts only the destination hostname instead of sending the full upload URL.

• Configuration

  • Adds screencapture_upload_identity_headers convar.
  • Enabled by default.
  • Set to false, 0, no, or off to disable identity headers.

• Header behavior

  • Existing user-provided upload headers continue to work.
  • User headers override generated defaults.

• Documentation

  • Documents the privacy impact and opt-out behavior for screenshot and video remote uploads.

set screencapture_upload_identity_headers false