feat: Add specific shift date field for multi-day events with date selector in EventEditor and date badge in ShiftMatrix

backend/apps/events/models.py

@@ -39,13 +39,15 @@ class TaskArea(models.Model):
 class Shift(models.Model):
     task_area = models.ForeignKey(TaskArea, on_delete=models.CASCADE, related_name='shifts')
     title = models.CharField(max_length=150)  # e.g., "Frühschicht", "14:00 - 18:00"
+    date = models.DateField(null=True, blank=True, help_text="Spezifisches Datum für mehrtägige Veranstaltungen")
     start_time = models.CharField(max_length=50)  # e.g. "14:00" or ISO string
     end_time = models.CharField(max_length=50)    # e.g. "18:00" or ISO string
     max_participants = models.PositiveIntegerField(default=1)
     required_skills = models.ManyToManyField(Skill, blank=True, related_name='shifts')
 
     def __str__(self):
-        return f"{self.task_area.name}: {self.title} ({self.start_time} - {self.end_time})"
+        date_str = f" ({self.date.strftime('%d.%m.%Y')})" if self.date else ""
+        return f"{self.task_area.name}: {self.title}{date_str} ({self.start_time} - {self.end_time})"
 
 class ShiftSignup(models.Model):
     shift = models.ForeignKey(Shift, on_delete=models.CASCADE, related_name='signups')