chore: adopt StrEnum and auto() for some string-typed enums (#25129)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: crazywoola <100913391+crazywoola@users.noreply.github.com>

api/commands.py

@@ -477,12 +477,12 @@ def convert_to_agent_apps():
             click.echo(f"Converting app: {app.id}")
 
             try:
-                app.mode = AppMode.AGENT_CHAT.value
+                app.mode = AppMode.AGENT_CHAT
                 db.session.commit()
 
                 # update conversation mode to agent
                 db.session.query(Conversation).where(Conversation.app_id == app.id).update(
-                    {Conversation.mode: AppMode.AGENT_CHAT.value}
+                    {Conversation.mode: AppMode.AGENT_CHAT}
                 )
 
                 db.session.commit()