1. Hidden fields now respected in SPA
- Added isFieldHidden helper to check if PHP sets type to 'hidden'
- Country/state/city fields conditionally rendered based on API response
- Set default country value for hidden country fields (Indonesia-only stores)
2. Coupon discount now shows correct amount
- Added calculate_totals() before reading discount
- Changed coupons response to include {code, discount, type} per coupon
- Added discount_total at root level for frontend compatibility
3. Order details page now shows shipping info and AWB tracking
- Added shipping_lines, tracking_number, tracking_url to Order interface
- Added Shipping Method section with courier name and cost
- Added AWB tracking section for processing/completed orders
- Track Shipment button with link to tracking URL