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
Store and close POSIX PTY master descriptors when terminal sessions are closed or killed, and make local terminal session shutdown await the full TTY cleanup path. This prevents leaked /dev/ptmx descriptors from exhausting the process file descriptor limit.
