os_system_tools
os_system_tools adds the operating system's clean default utility path to dependent tasks. It is a dependency, not a function, and takes no arguments.
Task environments otherwise start with an empty PATH. Declare os_system_tools when a build knowingly uses standard host commands instead of managed tools. The system directories are appended after paths supplied by other dependencies, so managed tools retain priority.
This enforces explicit dependencies; it does not make tasks hermetic. Absolute executable paths and scripts with absolute shebang interpreters can still access host tools because xx does not provide a filesystem sandbox.
Example
load("@os@1", "os_run", "os_system_tools")
os_run(("git", "status", "--short"), deps=[os_system_tools])