With BaseEnvironment supplying a backend-scoped probe to every production
caller, the module-level host-only `_sudo_nopasswd_works` (and its
TERMINAL_ENV gate) had no callers left; the `or` fallback and the outer
try/except around a callback that already fails closed were dead too.
Move the probe under `should_prompt_for_sudo`: headless callers (gateway,
cron, delegated children) reach `(command, None)` whether or not the probe
runs, so the extra backend round trip — an ssh exec on the SSH backend —
was pure waste on every headless sudo command.
test_subagent_sudo_prompt no longer needs to patch the host probe out:
bare `_transform_sudo_command(cmd)` calls have no probe by construction.
tools/approval.py no longer re-exports sibling names (approval_context/prompt/floors/detection/
human_wait/smart/gateway_wait); it imports only what it uses. Siblings reference sibling-defined
names directly (module-attribute reads on tools.approval_context so patching the defining module
still works); only facade-owned state (_lock, _gateway_queues, _permanent_approved, _denied,
_denial_breaker_addendum, _gateway_notify_cb) is still read back through tools.approval.
approval_detection calls its own _command_detection_variants instead of late-binding through the facade.