M1.4: Boot-test ISO in QEMU/KVM and VirtualBox (BIOS + UEFI)

[mshafiee]

Acceptance criteria

• Plasma desktop reaches QEMU/KVM BIOS
• Plasma desktop reaches QEMU/KVM UEFI
• Plasma desktop reaches VirtualBox BIOS
• Plasma desktop reaches VirtualBox UEFI
• Vazirmatn renders Persian
• us/ir toggle works
• apt update is clean

Dependencies

• M1.1b tagged artifact
• R2 bucket + download URL
• Cloudflare HTTPS enforcement

Notes

Use testing-qa-checklist.md §1–§3 as the acceptance gate.