fix(cli): confine agent runtime paths

README.md

@@ -64,6 +64,8 @@ async def main():
 
 The SDK includes a CLI for installing audit hooks into AI coding agents.
 
+Agent IDs map to one physical directory directly under `~/.elydora`; path separators, traversal segments, Windows reserved names, and symbolic-link directories are rejected.
+
 ```bash
 elydora install \
   --agent claudecode \