feat: Add real-time quiz lobby functionality

- Implement WebSocket-based lobby system for quiz participants
- Add lobby page with real-time participant updates
- Create LobbyConsumer for WebSocket communication
- Add routing configuration for WebSocket connections
- Update requirements with WebSocket dependencies
- Add development and production server documentation

This change enables real-time quiz lobbies where participants can
join and wait for the quiz to start, with instant updates for all
connected users.

django/play/models.py

@@ -6,13 +6,13 @@ import random, string
 
 # Create your models here.
 class QuizGame(models.Model):
-    host_user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='host_user')
+    host_id = models.CharField(max_length=200, unique=True)
     join_code = models.CharField(max_length=6, unique=True, blank=True)
     quiz_id = models.ForeignKey(QivipQuiz, on_delete=models.CASCADE)
 
     def save(self, *args, **kwargs):
         if not self.join_code:
-            self.join_code = self.generate_unique_code()
+            self.join_code = self.generate_unique_code()        
         super().save(*args, **kwargs)
 
     def generate_unique_code(self):
@@ -21,12 +21,19 @@ class QuizGame(models.Model):
             if not QuizGame.objects.filter(join_code=new_code).exists():
                 return new_code
 
+    def generate_unique_id(self):
+        for i in range(10):
+            new_id = ''.join(random.choices(string.digits + string.ascii_lowercase, k=60))
+            if not QuizGameParticipant.objects.filter(participant_id=new_id).exists():
+                return new_id
+
 class QuizGameParticipant(models.Model):
     participant_id = models.CharField(max_length=200, unique=True)
     display_name = models.CharField(verbose_name="Anzeigename", max_length=15)
     quiz_game = models.ForeignKey(QuizGame, on_delete=models.CASCADE, related_name="participant")
     score = models.IntegerField(verbose_name="Punkte", default=0)
     avatar = models.CharField(max_length=200, blank=True, default="")
+    last_heartbeat = models.DateTimeField(auto_now=True)
 
     def save(self, *args, **kwargs):
         if not self.participant_id: