fix: validate /model values before saving

tests/hermes_cli/test_model_validation.py

@@ -0,0 +1,43 @@
+"""Tests for provider-aware `/model` validation."""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))
+
+from hermes_cli.models import validate_requested_model
+
+
+class TestValidateRequestedModel:
+    def test_known_openrouter_model_can_be_saved(self):
+        result = validate_requested_model("anthropic/claude-opus-4.6", "openrouter")
+
+        assert result["accepted"] is True
+        assert result["persist"] is True
+        assert result["recognized"] is True
+        assert result["message"] is None
+
+    def test_openrouter_requires_provider_model_format(self):
+        result = validate_requested_model("claude-opus-4.6", "openrouter")
+
+        assert result["accepted"] is False
+        assert result["persist"] is False
+        assert "provider/model" in result["message"]
+
+    def test_unknown_codex_model_is_session_only(self):
+        result = validate_requested_model("totally-made-up", "openai-codex")
+
+        assert result["accepted"] is True
+        assert result["persist"] is False
+        assert "OpenAI Codex" in result["message"]
+
+    def test_custom_endpoint_allows_plain_model_ids(self):
+        result = validate_requested_model(
+            "gpt-4",
+            "openrouter",
+            base_url="http://localhost:11434/v1",
+        )
+
+        assert result["accepted"] is True
+        assert result["persist"] is True
+        assert result["message"] is None