fix(env_loader): log routed-scope dotenv skip once per home; port single-profile control test

Follow-up to the #77592 salvage: emit a once-per-home debug line where the
multiplex guard skips the process-global dotenv load (requested on #77562),
and port the single-profile control test from #77970 so the guard is pinned
to the multiplex flag rather than the home override alone.

Co-authored-by: DonShelly <25538402+DonShelly@users.noreply.github.com>

hermes_cli/env_loader.py

@@ -51,6 +51,10 @@ _SECRET_SOURCE_VALUES_BY_HOME: dict[str, dict[str, str]] = {}
 _APPLIED_HOMES: set[str] = set()
 _SECRET_SOURCE_CACHE_LOCK = threading.RLock()
 
+# Routed profile homes whose dotenv load was skipped under multiplex, so the
+# skip is logged once per home rather than on every lazy import mid-turn.
+_SCOPED_SKIP_LOGGED: set[str] = set()
+
 
 def _known_hermes_env_keys() -> set[str]:
     """Return the combined set of known Hermes env-var keys.
@@ -501,6 +505,16 @@ def load_hermes_dotenv(
     from hermes_constants import get_hermes_home_override
 
     if is_multiplex_active() and get_hermes_home_override() is not None:
+        home_key = str(home_path.resolve())
+        if home_key not in _SCOPED_SKIP_LOGGED:
+            _SCOPED_SKIP_LOGGED.add(home_key)
+            import logging
+
+            logging.getLogger(__name__).debug(
+                "multiplex: skipping process-global dotenv load for routed "
+                "profile home %s (credentials resolve via the profile scope)",
+                home_path,
+            )
         if load_external_secrets:
             from hermes_cli import _early_recovery
 

tests/test_env_loader_secret_sources.py

@@ -174,6 +174,36 @@ def test_cold_profile_bitwarden_uses_profile_bootstrap_without_global_env(
     assert os.environ.get("ANTHROPIC_API_KEY") is None
 
 
+def test_single_profile_scoped_load_keeps_override_behavior(tmp_path, monkeypatch):
+    """Without multiplex, a scoped load keeps its historical override behaviour.
+
+    Ported from #77970 (@DonShelly): the guard must key on the multiplex flag,
+    not on the home override alone -- single-profile ``-p`` runs still load.
+    """
+    from agent import secret_scope
+    from hermes_constants import reset_hermes_home_override, set_hermes_home_override
+
+    monkeypatch.delenv("HERMES_TEST_SHARED_ADAPTER_CONFIG", raising=False)
+    other_home = tmp_path / "other"
+    other_home.mkdir()
+    (other_home / ".env").write_text("HERMES_TEST_SHARED_ADAPTER_CONFIG=second\n")
+
+    was_active = secret_scope.is_multiplex_active()
+    secret_scope.set_multiplex_active(False)
+    home_token = set_hermes_home_override(other_home)
+    try:
+        loaded = env_loader.load_hermes_dotenv(hermes_home=other_home)
+    finally:
+        secret_scope.set_multiplex_active(was_active)
+        reset_hermes_home_override(home_token)
+
+    try:
+        assert os.environ.get("HERMES_TEST_SHARED_ADAPTER_CONFIG") == "second"
+        assert (other_home / ".env") in loaded
+    finally:
+        os.environ.pop("HERMES_TEST_SHARED_ADAPTER_CONFIG", None)
+
+
 def test_multiplex_dotenv_load_hydrates_sources_without_global_env(
     tmp_path, monkeypatch
 ):