Voucher redemption, Background Removal upload fixes, and chat-launcher polish.

Subscriptions

• Redeeming a voucher in the dashboard now properly applies it to your subscription end-to-end, with a copyable voucher code on the success card.
• "Gift Voucher Code" is now simply "Voucher Code" for clarity.
• The Subscription tab auto-opens when a gift code is valid, so the discount applies in the right place.

Sharing & Uploads

• Uploading multiple background images at once now correctly saves each image, and removing an existing backdrop works as expected.

Chat Support

• The Intercom live-chat launcher is now hidden on the public slideshow view.