Currently agentic apps have no universal standard to hide or block files from LLM agents, and hiding the existence of files is not perfect.
Basically, ignlnk replaces files with placeholder stubs when you lock them (originals go to a vault), and replaces those placeholders with symlinks when you unlock.
Of course, this is assuming the agents are not malicious. It only prevents less capable agents accidentally read, write or leak content of private files.