TestPixletEditorHostDefaultsButDoesNotOverride patched Popen on the shared
subprocess module. The app's before_request captive-portal hook runs
subprocess.run (`with Popen(...) as p`) for `systemctl is-active hostapd`
whenever its 30s AP-mode cache is cold, so on a Linux host with systemctl -
the CI runner - the hook got the FakeProcess and the request 500'd with
"'FakeProcess' object does not support the context manager protocol".
Whether it happened depended on how long ago the previous request ran,
hence the intermittency; Windows has no systemctl and never reached it.
- Patch the starlark route module's own `subprocess` binding instead of
the global Popen.
- Pin is_ap_mode_active to False in this file's client fixture, so no
request here shells out to systemctl/nmcli at all.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
