M3.2: Calamares branding (slideshow + welcome screen + Tehran/locale presets)

[mshafiee]

Acceptance criteria

• Custom Calamares slideshow/media committed
• Branded welcome screen applied
• Tehran timezone (Asia/Tehran) auto-detected/suggested in installer UI
• Persian locale presets configured in installer UI

Scope

Per project-next-steps.md M3.2 "Calamares Branding":

• Custom slideshow/media.
• Branded welcome screen.
• Tehran timezone + Persian locale presets in installer UI.

Dependencies

• M2.1 branding assets (Plymouth/SDDM themes, wallpapers) delivered
• M1.4 stable release baseline

Notes

Repo: iso-builder (Calamares config). Branding assets come from branding-assets M2.1. QA validation: testing-qa-checklist.md §2 (Tehran timezone detection).