Reverts workarounds added by the 361 agent when the hardened Docker
container broke the test suite:
- gates.rs: restore tempfile::tempdir() (was changed to tempdir_in
CARGO_MANIFEST_DIR to avoid noexec /tmp; noexec is now removed)
- pool/mod.rs: restore ps -p <pid> check in process_is_running (was
changed to /proc/<pid> existence check; procps is now installed)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
8094d32cbb