Refactor: file api in to seperate api app & use drf api views

backend/api/files/serializers.py

@@ -0,0 +1,32 @@
+from rest_framework import serializers
+from apps.files.models import PostFileModel
+
+
+class PostFileSerializer(serializers.ModelSerializer):
+    """Serializer for PostFileModel."""
+
+    class Meta:
+        model = PostFileModel
+        fields = ["hash_blake3", "file_type", "file", "thumbnail"]
+        # Add any other fields you need
+
+    def to_representation(self, instance):
+        """Customize the representation of the model."""
+        representation = super().to_representation(instance)
+
+        # Add file name from related model
+        try:
+            representation["filename"] = instance.name.first().filename
+        except (AttributeError, IndexError):
+            representation["filename"] = "Unknown"
+
+        # Add URLs for different thumbnail sizes
+        base_url = f"/api/files/{instance.hash_blake3}/"
+        thumbnails = {}
+        for size_key in THUMBNAIL_SIZES:
+            thumbnails[size_key] = f"{base_url}?t={size_key}"
+
+        representation["thumbnails"] = thumbnails
+        representation["download_url"] = f"{base_url}?d=0"
+
+        return representation