✨(frontend) allow starting both a recording and a transcription

Major user feature request: allow starting recording and transcription
simultaneously. Inspired by Google Meet UX, add a subtle checkbox letting users
start a recording alongside transcription.

The backend support for this feature is not yet implemented and will come in
upcoming commits, I can only pass the options to the API. The update of the
notification service will be handled later.
We’re half way with a functional feature.

This is not enabled by default because screen recording is resource-intensive. I
prefer users opt in rather than making it their default choice until feature
usage and performance stabilize.

src/backend/core/api/serializers.py

@@ -181,6 +181,7 @@ class RecordingSerializer(serializers.ModelSerializer):
             "updated_at",
             "status",
             "mode",
+            "options",
             "key",
             "is_expired",
             "expired_at",
@@ -212,6 +213,11 @@ class StartRecordingSerializer(BaseValidationOnlySerializer):
             "screen_recording or transcript.",
         },
     )
+    options = serializers.JSONField(
+        required=False,
+        allow_null=True,
+        default=dict,
+    )
 
 
 class RequestEntrySerializer(BaseValidationOnlySerializer):