fix: Incorrect RR host is shown in the email and calendar event for a seated RR event (calcom#21684)

* fix: seated rr event

* Update packages/features/bookings/lib/handleNewBooking.ts

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

* update

* Update handleNewBooking.ts

---------

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

Author: anikdhabal

packages/features/bookings/lib/handleNewBooking.ts

@@ -650,9 +650,31 @@ async function handler(
         startTime: new Date(dayjs(reqBody.start).utc().format()),
         status: BookingStatus.ACCEPTED,
       },
+      select: {
+        userId: true,
+        attendees: { select: { email: true } },
+      },
     });
 
-    if (booking) isFirstSeat = false;
+    if (booking) {
+      isFirstSeat = false;
+      if (eventType.schedulingType === SchedulingType.ROUND_ROBIN) {
+        const fixedHosts = users.filter((user) => user.isFixed);
+        const originalNonFixedHost = users.find((user) => !user.isFixed && user.id === booking.userId);
+
+        if (originalNonFixedHost) {
+          users = [...fixedHosts, originalNonFixedHost];
+        } else {
+          const attendeeEmailSet = new Set(booking.attendees.map((attendee) => attendee.email));
+
+          // In this case, the first booking user is a fixed host, so the chosen non-fixed host is added as an attendee of the booking
+          const nonFixedAttendeeHost = users.find(
+            (user) => !user.isFixed && attendeeEmailSet.has(user.email)
+          );
+          users = [...fixedHosts, ...(nonFixedAttendeeHost ? [nonFixedAttendeeHost] : [])];
+        }
+      }
+    }
   }
 
   //checks what users are available