fix(cli): warn when --provider default_model cannot be resolved

A named --provider without -m used to swallow lookup failures and
silently keep the global model.default. Log the resolution error so
the fallback is visible.

cli.py

@@ -4865,7 +4865,13 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin, CLIBillingMixin):
                 from hermes_cli.runtime_provider import _get_named_custom_provider
 
                 _named_custom = _get_named_custom_provider(provider)
-            except Exception:
+            except Exception as exc:
+                logger.warning(
+                    "Could not resolve --provider %s default model; "
+                    "keeping global model.default (%s)",
+                    provider,
+                    exc,
+                )
                 _named_custom = None
             _provider_default = str((_named_custom or {}).get("model") or "").strip()
             if _provider_default:

tests/cli/test_cli_provider_resolution.py

@@ -183,6 +183,33 @@ def test_explicit_model_wins_over_provider_default_model(monkeypatch):
     assert shell.model == "explicit-id"
 
 
+def test_provider_flag_logs_when_custom_default_model_cannot_resolve(monkeypatch, caplog):
+    """A named --provider that fails to resolve must not fail silently."""
+    cli = _import_cli()
+    monkeypatch.setitem(
+        cli.CLI_CONFIG,
+        "model",
+        {"default": "tencent/hy3:free", "provider": "nous"},
+    )
+
+    def _boom(_name):
+        raise RuntimeError("catalog unavailable")
+
+    monkeypatch.setattr(
+        "hermes_cli.runtime_provider._get_named_custom_provider",
+        _boom,
+    )
+
+    with caplog.at_level("WARNING"):
+        shell = cli.HermesCLI(provider="gmk-lan", compact=True, max_turns=1)
+
+    assert shell.model == "tencent/hy3:free"
+    assert any(
+        "gmk-lan" in rec.getMessage() and "catalog unavailable" in rec.getMessage()
+        for rec in caplog.records
+    )
+
+
 def test_hermes_cli_init_does_not_eagerly_resolve_runtime_provider(monkeypatch):
     cli = _import_cli()
     calls = {"count": 0}