Implement upgrade `.zip` staging and extraction logic

[hakiatalov]

As the BLIS-NG Update Service,
I want to ingest, stage, and extract a .zip update payload from an external USB volume to a local staging directory,
So that the system has all necessary files locally to perform an upgrade, allowing the user to safely remove the physical USB drive.

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AC

1. Verification and Staging

   • Given a .zip file exists on a mounted USB drive, when the upload is triggered, then the system must copy the file to staging\.
   • The system must verify that the disk has sufficient space before starting the transfer.

2. Extraction

   • When the copy is complete, the system must extract the contents into the staging directory.

3. Error Handling

   • If the .zip file fails to copy or extract, or there is insufficient disk space, the system must notify the user.

[hakiatalov]

@luqmanrashad first story