Local is a location, not a promise
A local backend changes where the application runs and stores its history. It does not change where an external API runs. Audio, screenshots and references can leave the device when the feature you requested needs them.
Capture only what you need
Select the relevant source, review screen context before submitting it and stop sessions when finished. Avoid including unrelated windows, credentials or confidential material in a screenshot.
Give protection an honest name
Operating-system capture protection can help exclude an app window from supported capture methods. It cannot promise invisibility to every capture device or application. Test the actual setup and follow the rules of the conversation.