6 Gulf country profiles (KSA 15% SAR, UAE 5% AED, Bahrain 10% BHD, Oman 5% OMR, Qatar/Kuwait 0%), per-line VAT with inclusive/exclusive toggle, zero-rated/export lines, Arabic + English with RTL, sequential invoice numbering, draft/issued status, PDF export, WhatsApp share, Phase 1-style QR payload.