fix: prioritize OPENROUTER_API_KEY over OPENAI_API_KEY

When both OPENROUTER_API_KEY and OPENAI_API_KEY are set (e.g. OPENAI_API_KEY
in .bashrc), the wrong key was sent to OpenRouter causing auth failures.

Fixed key resolution order in cli.py and runtime_provider.py.

Fixes #289

hermes_cli/runtime_provider.py

@@ -74,8 +74,8 @@ def _resolve_openrouter_runtime(
 
     api_key = (
         explicit_api_key
-        or os.getenv("OPENAI_API_KEY")
         or os.getenv("OPENROUTER_API_KEY")
+        or os.getenv("OPENAI_API_KEY")
         or ""
     )