fix(tui): resolve startup model aliases statically

- expand short model aliases like sonnet/opus via static catalogs during startup runtime resolution
- keep startup alias resolution network-free and add regression tests in models and tui gateway suites

tests/hermes_cli/test_models.py

@@ -256,6 +256,17 @@ class TestDetectProviderForModel:
         """Models belonging to the current provider should not trigger a switch."""
         assert detect_provider_for_model("gpt-5.3-codex", "openai-codex") is None
 
+    def test_short_alias_resolves_to_static_model(self):
+        """Short aliases (e.g. sonnet) should resolve without network lookups."""
+        with patch(
+            "hermes_cli.models.fetch_openrouter_models",
+            side_effect=AssertionError("network lookup should not run"),
+        ):
+            result = detect_provider_for_model("sonnet", "auto")
+        assert result is not None
+        assert result[0] == "anthropic"
+        assert result[1].startswith("claude-sonnet")
+
     def test_openrouter_slug_match(self):
         """Models in the OpenRouter catalog should be found."""
         with patch("hermes_cli.models.fetch_openrouter_models", return_value=LIVE_OPENROUTER_MODELS):