Fix billing summary to use annualized seat price instead of raw Stripe unit amount

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: simonhamp

app/Livewire/TeamManager.php

@@ -180,8 +180,8 @@ public function render()
                     $qty = $item->quantity ?? 1;
 
                     if (Subscription::isExtraSeatPrice($item->price->id)) {
-                        $seatsCost = $unitAmount * $qty;
                         $extraSeatsQty = $qty;
+                        $seatsCost = $extraSeatPrice * $qty;
                     } else {
                         $planPrice = $unitAmount;
                     }