fix(cli): narrow Nous Hermes non-agentic warning to actual hermes-3/-4 models

The startup warning that Nous Research Hermes 3 & 4 models are not agentic
fired on any model whose name contained "hermes" anywhere, via a plain
substring check. That false-positived on unrelated local Modelfiles such
as `hermes-brain:qwen3-14b-ctx16k` — a tool-capable Qwen3 wrapper that
happens to live under a custom "hermes" tag namespace — making the warning
noise for legitimate setups.

Replace the substring check with a narrow regex anchored on `^`, `/`, or
`:` boundaries that only matches the real Hermes-3 / Hermes-4 chat family
(e.g. `NousResearch/Hermes-3-Llama-3.1-70B`, `hermes-4-405b`,
`openrouter/hermes3:70b`). Consolidate into a single helper
`is_nous_hermes_non_agentic()` in `hermes_cli.model_switch` so the CLI
and the canonical check don't drift, and route the duplicate inline site
in `cli.HermesCLI._print_warnings()` through the helper.

Add a parametrized test covering positive matches (real Hermes-3/-4
names) and a broad set of negatives (custom Modelfiles, Qwen/Claude/GPT,
older Nous-Hermes-2 families, bare "hermes", empty string, and the
"brain-hermes-3-impostor" boundary case).

tests/hermes_cli/test_nous_hermes_non_agentic.py

@@ -0,0 +1,84 @@
+"""Tests for the Nous-Hermes-3/4 non-agentic warning detector.
+
+Prior to this check, the warning fired on any model whose name contained
+``"hermes"`` anywhere (case-insensitive). That false-positived on unrelated
+local Modelfiles such as ``hermes-brain:qwen3-14b-ctx16k`` — a tool-capable
+Qwen3 wrapper that happens to live under the "hermes" tag namespace.
+
+``is_nous_hermes_non_agentic`` should only match the actual Nous Research
+Hermes-3 / Hermes-4 chat family.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from hermes_cli.model_switch import (
+    _HERMES_MODEL_WARNING,
+    _check_hermes_model_warning,
+    is_nous_hermes_non_agentic,
+)
+
+
+@pytest.mark.parametrize(
+    "model_name",
+    [
+        "NousResearch/Hermes-3-Llama-3.1-70B",
+        "NousResearch/Hermes-3-Llama-3.1-405B",
+        "hermes-3",
+        "Hermes-3",
+        "hermes-4",
+        "hermes-4-405b",
+        "hermes_4_70b",
+        "openrouter/hermes3:70b",
+        "openrouter/nousresearch/hermes-4-405b",
+        "NousResearch/Hermes3",
+        "hermes-3.1",
+    ],
+)
+def test_matches_real_nous_hermes_chat_models(model_name: str) -> None:
+    assert is_nous_hermes_non_agentic(model_name), (
+        f"expected {model_name!r} to be flagged as Nous Hermes 3/4"
+    )
+    assert _check_hermes_model_warning(model_name) == _HERMES_MODEL_WARNING
+
+
+@pytest.mark.parametrize(
+    "model_name",
+    [
+        # Kyle's local Modelfile — qwen3:14b under a custom tag
+        "hermes-brain:qwen3-14b-ctx16k",
+        "hermes-brain:qwen3-14b-ctx32k",
+        "hermes-honcho:qwen3-8b-ctx8k",
+        # Plain unrelated models
+        "qwen3:14b",
+        "qwen3-coder:30b",
+        "qwen2.5:14b",
+        "claude-opus-4-6",
+        "anthropic/claude-sonnet-4.5",
+        "gpt-5",
+        "openai/gpt-4o",
+        "google/gemini-2.5-flash",
+        "deepseek-chat",
+        # Non-chat Hermes models we don't warn about
+        "hermes-llm-2",
+        "hermes2-pro",
+        "nous-hermes-2-mistral",
+        # Edge cases
+        "",
+        "hermes",  # bare "hermes" isn't the 3/4 family
+        "hermes-brain",
+        "brain-hermes-3-impostor",  # "3" not preceded by /: boundary
+    ],
+)
+def test_does_not_match_unrelated_models(model_name: str) -> None:
+    assert not is_nous_hermes_non_agentic(model_name), (
+        f"expected {model_name!r} NOT to be flagged as Nous Hermes 3/4"
+    )
+    assert _check_hermes_model_warning(model_name) == ""
+
+
+def test_none_like_inputs_are_safe() -> None:
+    assert is_nous_hermes_non_agentic("") is False
+    # Defensive: the helper shouldn't crash on None-ish falsy input either.
+    assert _check_hermes_model_warning("") == ""