Show combined price for round trip bookings in the list

Now that only the outbound leg gets a row, its Price column showed just
that leg's price, silently missing the return leg's half. It now sums both
legs (bcadd, 2dp) for a round trip, with a breakdown shown underneath;
unchanged for one-way bookings.

app-modules/booking/tests/Feature/BookingResourceTest.php

@@ -360,6 +360,26 @@ test('a round trip\'s return leg has no row of its own in the list, only its out
         ->assertCanNotSeeTableRecords([$return]);
 });
 
+test('a round trip\'s price column shows both legs combined', function () {
+    $outbound = Booking::factory()->create(['is_return_leg' => false, 'price' => 15000]);
+    $return = Booking::factory()->create([
+        'is_return_leg' => true,
+        'linked_booking_id' => $outbound->id,
+        'price' => 20000,
+    ]);
+    $outbound->update(['linked_booking_id' => $return->id]);
+
+    Livewire::test(ListBookings::class)
+        ->assertTableColumnStateSet('price', '35000.00', record: $outbound);
+});
+
+test('a one-way booking\'s price column shows just its own price', function () {
+    $booking = Booking::factory()->create(['is_return_leg' => false, 'linked_booking_id' => null, 'price' => 15000]);
+
+    Livewire::test(ListBookings::class)
+        ->assertTableColumnStateSet('price', '15000.00', record: $booking);
+});
+
 test('the restore action is only visible for a trashed booking', function () {
     $active = Booking::factory()->create();
     $deleted = Booking::factory()->create();