Refactor database models to majorly increase queries needed and decrease load times of home from 30 secs to 5 sec (we will be caching the rest to decrease even further via background tasks)

cards/signals.py

@@ -0,0 +1,17 @@
+from django.db.models.signals import m2m_changed
+from django.dispatch import receiver
+from .models import Card
+
+@receiver(m2m_changed, sender=Card.decks.through)
+def update_card_style(sender, instance, action, **kwargs):
+    if action == "post_add":
+        decks = instance.decks.all()
+        num_decks = decks.count()
+        if num_decks == 1:
+            instance.style = "background-color: " + decks.first().hex_color + ";"
+        elif num_decks >= 2:
+            hex_colors = [deck.hex_color for deck in decks]
+            instance.style = f"background: linear-gradient(to right, {', '.join(hex_colors)});"
+        else:
+            instance.style = "background: linear-gradient(to right, #AAAAAA, #AAAAAA, #AAAAAA);"
+        instance.save(update_fields=["style"])