fix(update): keep get_hermes_home late-bound in _install_hangup_protection

Follow-up to the redundant-imports sweep. _install_hangup_protection
used to import get_hermes_home locally; the sweep hoisted it to the
module-level binding already present at line 164.

test_non_fatal_if_log_setup_fails monkeypatches
hermes_cli.config.get_hermes_home to raise, which only works when the
function late-binds its lookup. The hoisted version captures the
reference at import time and bypasses the monkeypatch.

Restore the local import (with a distinct local alias) so the test
seam works and the stdio-untouched-on-setup-failure invariant is
actually exercised.

hermes_cli/main.py

@@ -5212,7 +5212,11 @@ def _install_hangup_protection(gateway_mode: bool = False):
     # (2) Mirror output to update.log and wrap stdio for broken-pipe
     # tolerance.  Any failure here is non-fatal; we just skip the wrap.
     try:
-        logs_dir = get_hermes_home() / "logs"
+        # Late-bound import so tests can monkeypatch
+        # hermes_cli.config.get_hermes_home to simulate setup failure.
+        from hermes_cli.config import get_hermes_home as _get_hermes_home
+
+        logs_dir = _get_hermes_home() / "logs"
         logs_dir.mkdir(parents=True, exist_ok=True)
         log_path = logs_dir / "update.log"
         log_file = open(log_path, "a", buffering=1, encoding="utf-8")