Cross-Vendor Price Aggregation for Instant Sell

The Instant Sell feature in the Reusely inventory view should be upgraded to display buyback offers from all integrated vendors simultaneously. Currently, users only see the price from the single wholesaler they have active for Price Sync, hiding potentially higher offers from other sources.

This multi-vendor pricing should appear directly within the inventory list or as a quick-view breakdown, allowing users to compare payouts from all connected datafeeds at a glance. By removing the need to manually toggle sync sources to find the best deal, this update enables faster liquidation and ensures users always capture the highest possible margin on their devices.