fix(config): reload .env over stale shell overrides

Hermes startup entrypoints now load ~/.hermes/.env and project fallback env files with user config taking precedence over stale shell-exported values. This makes model/provider/base URL changes in .env actually take effect after restarting Hermes. Adds a shared env loader plus regression coverage, and reproduces the original bug case where OPENAI_BASE_URL and HERMES_INFERENCE_PROVIDER remained stuck on old shell values before import.

hermes_cli/env_loader.py

@@ -0,0 +1,46 @@
+"""Helpers for loading Hermes .env files consistently across entrypoints."""
+
+from __future__ import annotations
+
+import os
+from pathlib import Path
+from typing import Iterable
+
+from dotenv import load_dotenv
+
+
+def _load_dotenv_with_fallback(path: Path, *, override: bool) -> None:
+    try:
+        load_dotenv(dotenv_path=path, override=override, encoding="utf-8")
+    except UnicodeDecodeError:
+        load_dotenv(dotenv_path=path, override=override, encoding="latin-1")
+
+
+def load_hermes_dotenv(
+    *,
+    hermes_home: str | os.PathLike | None = None,
+    project_env: str | os.PathLike | None = None,
+) -> list[Path]:
+    """Load Hermes environment files with user config taking precedence.
+
+    Behavior:
+    - `~/.hermes/.env` overrides stale shell-exported values when present.
+    - project `.env` acts as a dev fallback and only fills missing values when
+      the user env exists.
+    - if no user env exists, the project `.env` also overrides stale shell vars.
+    """
+    loaded: list[Path] = []
+
+    home_path = Path(hermes_home or os.getenv("HERMES_HOME", Path.home() / ".hermes"))
+    user_env = home_path / ".env"
+    project_env_path = Path(project_env) if project_env else None
+
+    if user_env.exists():
+        _load_dotenv_with_fallback(user_env, override=True)
+        loaded.append(user_env)
+
+    if project_env_path and project_env_path.exists():
+        _load_dotenv_with_fallback(project_env_path, override=not loaded)
+        loaded.append(project_env_path)
+
+    return loaded