🎉(all) bootstrap the Calendars project

This repository was forked from Drive in late December 2025 and
boostraped as a minimal demo of backend+caldav server+frontend
integration. There is much left to do and to fix!

src/backend/core/api/fields.py

@@ -0,0 +1,25 @@
+"""A JSONField for DRF to handle serialization/deserialization."""
+
+import json
+
+from rest_framework import serializers
+
+
+class JSONField(serializers.Field):
+    """
+    A custom field for handling JSON data.
+    """
+
+    def to_representation(self, value):
+        """
+        Convert the JSON string to a Python dictionary for serialization.
+        """
+        return value
+
+    def to_internal_value(self, data):
+        """
+        Convert the Python dictionary to a JSON string for deserialization.
+        """
+        if data is None:
+            return None
+        return json.dumps(data)