Add selected branch to convo metadata (#6773)

openhands/server/routes/manage_conversations.py

@@ -100,6 +100,7 @@ async def _create_new_conversation(
             title=conversation_title,
             github_user_id=user_id,
             selected_repository=selected_repository,
+            selected_branch=selected_branch,
         )
     )
 

openhands/storage/data_models/conversation_metadata.py

@@ -7,6 +7,7 @@ class ConversationMetadata:
     conversation_id: str
     github_user_id: str | None
     selected_repository: str | None
+    selected_branch: str | None = None
     title: str | None = None
     last_updated_at: datetime | None = None
     created_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))