Host file copying via plugin path traversal

Path traversal in Microsoft APM before 0.8.12 allows attackers to copy readable host files through a malicious plugin. The _resolve_sources() method joins attacker-controlled agents, skills, commands, and hooks values to the plugin root, checks only existence and symlink status, and copies the resulting paths without resolving and enforcing root containment. Exploitation requires a user to install a malicious or compromised plugin; copied content can be written into managed output and project prompt paths.