✨(frontend) serialize recording key for frontend download links

Add recording key to serialized API response to enable frontend to generate
proper download links without additional backend calls. Simplifies media
access workflow across the application.

src/backend/core/api/serializers.py

@@ -156,7 +156,7 @@ class RecordingSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = models.Recording
-        fields = ["id", "room", "created_at", "updated_at", "status", "mode"]
+        fields = ["id", "room", "created_at", "updated_at", "status", "mode", "key"]
         read_only_fields = fields
 
 

src/backend/core/tests/recording/test_api_recordings_list.py

@@ -78,6 +78,7 @@ def test_api_recordings_list_authenticated_direct(role):
     assert expected_ids == result_ids
     assert results[0] == {
         "id": str(recording.id),
+        "key": recording.key,
         "created_at": recording.created_at.isoformat().replace("+00:00", "Z"),
         "mode": recording.mode,
         "room": {

src/backend/core/tests/recording/test_api_recordings_retrieve.py

@@ -80,6 +80,7 @@ def test_api_recording_retrieve_administrators():
 
     assert content == {
         "id": str(recording.id),
+        "key": recording.key,
         "room": {
             "access_level": str(room.access_level),
             "id": str(room.id),
@@ -111,6 +112,7 @@ def test_api_recording_retrieve_owners():
 
     assert content == {
         "id": str(recording.id),
+        "key": recording.key,
         "room": {
             "access_level": str(room.access_level),
             "id": str(room.id),