Document files can be read with open() and with-blocks (.read(),
.readline(), .readlines()); writes raise PermissionError. File objects
remain non-iterable and the collections module is still unavailable.
0.0.19 runs sandboxed code in a subprocess worker pool (AsyncMonty /
AsyncMontySession) and drops MontyRepl. The sandbox checks out a session,
drives it with feed_run, and closes it to return the worker; close() is
now async. Worker crashes surface as a failed SandboxResult. The document
VFS (OSAccess/CallbackFile/MemoryFile) is unchanged.
