Fix configuration for default voice model settings

src/khoj/database/adapters/__init__.py

@@ -752,7 +752,7 @@ class ConversationAdapters:
         voice_model_config = await UserVoiceModelConfig.objects.filter(user=user).prefetch_related("setting").afirst()
         if voice_model_config:
             return voice_model_config.setting
-        return None
+        return await VoiceModelOption.objects.afirst()
 
     @staticmethod
     def get_voice_model_options():
@@ -763,7 +763,7 @@ class ConversationAdapters:
         voice_model_config = UserVoiceModelConfig.objects.filter(user=user).prefetch_related("setting").first()
         if voice_model_config:
             return voice_model_config.setting
-        return None
+        return VoiceModelOption.objects.first()
 
     @staticmethod
     def get_default_conversation_config():

src/khoj/database/admin.py

@@ -27,6 +27,7 @@ from khoj.database.models import (
     Subscription,
     TextToImageModelConfig,
     UserSearchModelConfig,
+    UserVoiceModelConfig,
     VoiceModelOption,
 )
 from khoj.utils.helpers import ImageIntentType
@@ -99,6 +100,7 @@ admin.site.register(UserSearchModelConfig)
 admin.site.register(ClientApplication)
 admin.site.register(GithubConfig)
 admin.site.register(NotionConfig)
+admin.site.register(UserVoiceModelConfig)
 admin.site.register(VoiceModelOption)