[oi-dev] Live Media Writer Script - supports writing illumos images

[Atiq Rahman]

Hi Illumates,
Had an hour to kill at the airport lounge, got some some coffee and
this is what came out of it:
https://github.com/atiq-cs/Shell/blob/dev/admin/live-media-to-disk.nu

The script downloads the latest OI/OmniOS image, verifies sha256
checksum and writes the image on flash drive. Write is tested on linux
though, yet to test it on illumos though.

Here's an example run,

```
$ admin/live-media-to-disk.nu openindiana beta --gui
($env.Home)/soft/images/ /dev/sda

Image URL: https://dlc.openindiana.org/isos/hipster/test/OI-hipster-gui-20251011.usb
File OI-hipster-gui-20251011.usb already exists, skipping download.

=== Verification Stage ===
Verifying SHA-256 checksum...
[OK] SHA-256 verified for OI-hipster-gui-20251011.usb

=== All Verifications Passed ===
File ready: /home/atiq/soft/images/OI-hipster-gui-20251011.usb

About to write to /dev/sda using dd...
This will PERMANENTLY DESTROY all data on the target device!
Verify device with: lsblk
Type 'yes' to continue: yes

Executing: sudo dd bs=4M
if=/home/atiq/soft/images/OI-hipster-gui-20251011.usb of=/dev/sda
status=progress conv=fsync

[sudo] password for atiq:
2826960896 bytes (2.8 GB, 2.6 GiB) copied, 82 s, 34.4 MB/s2828809728
bytes (2.8 GB, 2.6 GiB) copied, 82.6832 s, 34.2 MB/s

674+1 records in
674+1 records out
2828809728 bytes (2.8 GB, 2.6 GiB) copied, 91.3796 s, 31.0 MB/s

[OK] Write complete. Syncing filesystem...
[OK] Device ready to boot.
```

Cheers!
Atiq