Paramiko caches its optional invoke import error with the original traceback, retaining the code-execution tool-loading stack and first agent.
Clear only the stale traceback while preserving the exception, and add focused regression coverage.
Clear DeferredTask callables and arguments after completion or cancellation while running each invocation from a safe private snapshot. Preserve result retrieval and active restart behavior, clean up child tasks, and add best-effort local and SSH session destructors with focused lifecycle regression coverage.
Detect and treat terminated local/SSH/TTY shells as definitive command completion. Add is_terminated and get_exit_code helpers to LocalInteractiveSession, SSHInteractiveSession, and TTYSession; expand _is_closed_pty_error to recognize exited TTY processes. CodeExecution now reports a shell-exit prompt, recreates terminated sessions lazily before the next command, and returns immediately when a shell has exited. Docs and README updated to describe strict-mode/exit behavior, and tests were added/updated to cover the new termination detection and handling.
The code execution tool runs commands inside TTY-backed shells (local PTY and
remote SSH). Commands like `git diff`/`git log` detect the TTY and pipe output
through a pager (more/less). These shells never receive interactive input, so
the pager blocks forever and spins at 100% CPU per process — on a 16-core host
5 pager processes pegged 5 cores for 8+ hours (#1697).
Disable pagers in both session types:
- LocalInteractiveSession: inject PAGER=cat / GIT_PAGER=cat into the TTY env
- SSHInteractiveSession: export the same in the initial shell command
`cat` streams the output through instead of blocking, and also covers other
pager-using tools (man, systemctl, journalctl). Adds regression tests.
Fixes#1697
