feat(src/tickets): add database indexes for performance

Improve query speed on Ticket, TicketComment, and TicketPriority by indexing fields used in frequent filters and ordering.

src/tickets/models.py

@@ -20,6 +20,9 @@ class TicketPriority(models.Model):
         db_table = "ticket_priorities"
         verbose_name = "Ticket Priority"
         verbose_name_plural = "Ticket Priorities"
+        indexes = [
+            models.Index(fields=["name"]),
+        ]
 
     def __str__(self):
         return self.name
@@ -103,6 +106,12 @@ class Ticket(models.Model):
             models.Index(fields=["due_date"]),
             models.Index(fields=["priority"]),
             models.Index(fields=["created_by"]),
+            models.Index(fields=["epic"]),
+            models.Index(fields=["name"]),
+            models.Index(fields=["start_date"]),
+            models.Index(fields=["project", "name"]),
+            models.Index(fields=["project", "start_date", "due_date"]),
+            models.Index(fields=["due_date", "status"]),
         ]
 
     def __str__(self):
@@ -190,6 +199,7 @@ class TicketComment(models.Model):
         verbose_name_plural = "Ticket Comments"
         indexes = [
             models.Index(fields=["ticket", "created_at"]),
+            models.Index(fields=["user"]),
         ]
 
     def __str__(self):