fix: guard validate_requested_model + expand test coverage (PR #649 follow-up)

- Wrap validate_requested_model in try/except so /model doesn't crash
  if validation itself fails (falls back to old accept+save behavior)
- Remove unnecessary sys.path.insert from both test files
- Expand test_model_validation.py: 4 → 23 tests covering normalize_provider,
  provider_model_ids, empty/whitespace/spaces rejection, OpenRouter format
  validation, custom endpoints, nous provider, provider aliases, unknown
  providers, fuzzy suggestions
- Expand test_cli_model_command.py: 2 → 5 tests adding known-model save,
  validation crash fallback, and /model with no argument

tests/hermes_cli/test_model_validation.py

@@ -1,15 +1,57 @@
-"""Tests for provider-aware `/model` validation."""
+"""Tests for provider-aware `/model` validation in hermes_cli.models."""
 
-import os
-import sys
+from hermes_cli.models import (
+    normalize_provider,
+    provider_model_ids,
+    validate_requested_model,
+)
 
-sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))
 
-from hermes_cli.models import validate_requested_model
+class TestNormalizeProvider:
+    def test_defaults_to_openrouter(self):
+        assert normalize_provider(None) == "openrouter"
+        assert normalize_provider("") == "openrouter"
+
+    def test_known_aliases(self):
+        assert normalize_provider("glm") == "zai"
+        assert normalize_provider("z-ai") == "zai"
+        assert normalize_provider("z.ai") == "zai"
+        assert normalize_provider("zhipu") == "zai"
+        assert normalize_provider("kimi") == "kimi-coding"
+        assert normalize_provider("moonshot") == "kimi-coding"
+        assert normalize_provider("minimax-china") == "minimax-cn"
+
+    def test_canonical_ids_pass_through(self):
+        assert normalize_provider("openrouter") == "openrouter"
+        assert normalize_provider("nous") == "nous"
+        assert normalize_provider("openai-codex") == "openai-codex"
+
+    def test_case_insensitive(self):
+        assert normalize_provider("OpenRouter") == "openrouter"
+        assert normalize_provider("GLM") == "zai"
+
+
+class TestProviderModelIds:
+    def test_openrouter_returns_curated_list(self):
+        ids = provider_model_ids("openrouter")
+        assert len(ids) > 0
+        assert all("/" in mid for mid in ids)
+
+    def test_unknown_provider_returns_empty(self):
+        assert provider_model_ids("some-unknown-provider") == []
+
+    def test_zai_returns_glm_models(self):
+        ids = provider_model_ids("zai")
+        assert "glm-5" in ids
+
+    def test_alias_resolves_correctly(self):
+        assert provider_model_ids("glm") == provider_model_ids("zai")
 
 
 class TestValidateRequestedModel:
-    def test_known_openrouter_model_can_be_saved(self):
+    # -- known models (happy path) ---------------------------------------
+
+    def test_known_openrouter_model_accepted_and_persisted(self):
         result = validate_requested_model("anthropic/claude-opus-4.6", "openrouter")
 
         assert result["accepted"] is True
@@ -17,13 +59,97 @@ class TestValidateRequestedModel:
         assert result["recognized"] is True
         assert result["message"] is None
 
-    def test_openrouter_requires_provider_model_format(self):
+    # -- empty / whitespace ----------------------------------------------
+
+    def test_empty_model_rejected(self):
+        result = validate_requested_model("", "openrouter")
+        assert result["accepted"] is False
+        assert "empty" in result["message"]
+
+    def test_whitespace_only_rejected(self):
+        result = validate_requested_model("   ", "openrouter")
+        assert result["accepted"] is False
+        assert "empty" in result["message"]
+
+    def test_model_with_spaces_rejected(self):
+        result = validate_requested_model("anthropic/ claude-opus", "openrouter")
+        assert result["accepted"] is False
+        assert "spaces" in result["message"].lower()
+
+    # -- OpenRouter format validation ------------------------------------
+
+    def test_openrouter_requires_slash(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_openrouter_rejects_leading_slash(self):
+        result = validate_requested_model("/claude-opus-4.6", "openrouter")
+        assert result["accepted"] is False
+
+    def test_openrouter_rejects_trailing_slash(self):
+        result = validate_requested_model("anthropic/", "openrouter")
+        assert result["accepted"] is False
+
+    def test_openrouter_unknown_but_plausible_is_session_only(self):
+        result = validate_requested_model("anthropic/claude-next-gen", "openrouter")
+
+        assert result["accepted"] is True
+        assert result["persist"] is False
+        assert result["recognized"] is False
+        assert "session only" in result["message"].lower()
+
+    # -- custom endpoint -------------------------------------------------
+
+    def test_custom_base_url_accepts_anything(self):
+        result = validate_requested_model(
+            "my-local-model",
+            "openrouter",
+            base_url="http://localhost:11434/v1",
+        )
+
+        assert result["accepted"] is True
+        assert result["persist"] is True
+        assert result["message"] is None
+
+    # -- nous provider ---------------------------------------------------
+
+    def test_nous_provider_is_session_only(self):
+        result = validate_requested_model("hermes-3", "nous")
+
+        assert result["accepted"] is True
+        assert result["persist"] is False
+        assert "Nous Portal" in result["message"]
+
+    # -- other providers with catalogs -----------------------------------
+
+    def test_known_zai_model_accepted_and_persisted(self):
+        result = validate_requested_model("glm-5", "zai")
+
+        assert result["accepted"] is True
+        assert result["persist"] is True
+        assert result["recognized"] is True
+
+    def test_unknown_zai_model_is_session_only(self):
+        result = validate_requested_model("glm-99", "zai")
+
+        assert result["accepted"] is True
+        assert result["persist"] is False
+        assert "Z.AI" in result["message"]
+
+    # -- provider with no catalog ----------------------------------------
+
+    def test_unknown_provider_is_session_only(self):
+        result = validate_requested_model("some-model", "totally-unknown")
+
+        assert result["accepted"] is True
+        assert result["persist"] is False
+        assert result["message"] is not None
+
+    # -- codex provider --------------------------------------------------
+
     def test_unknown_codex_model_is_session_only(self):
         result = validate_requested_model("totally-made-up", "openai-codex")
 
@@ -31,13 +157,11 @@ class TestValidateRequestedModel:
         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",
-        )
+    # -- fuzzy suggestions -----------------------------------------------
 
+    def test_close_match_gets_suggestion(self):
+        # Typo of a known model — should get a suggestion in the message
+        result = validate_requested_model("anthropic/claude-opus-4.5", "openrouter")
+        # May or may not match depending on cutoff, but should be session-only
         assert result["accepted"] is True
-        assert result["persist"] is True
-        assert result["message"] is None
+        assert result["persist"] is False