test: reorganize test structure and add missing unit tests

Reorganize flat tests/ directory to mirror source code structure
(tools/, gateway/, hermes_cli/, integration/). Add 11 new test files
covering previously untested modules: registry, patch_parser,
fuzzy_match, todo_tool, approval, file_tools, gateway session/config/
delivery, and hermes_cli config/models. Total: 147 unit tests passing,
9 integration tests gated behind pytest marker.

tests/hermes_cli/test_config.py

@@ -0,0 +1,68 @@
+"""Tests for hermes_cli configuration management."""
+
+import os
+from pathlib import Path
+from unittest.mock import patch
+
+from hermes_cli.config import (
+    DEFAULT_CONFIG,
+    get_hermes_home,
+    ensure_hermes_home,
+    load_config,
+    save_config,
+)
+
+
+class TestGetHermesHome:
+    def test_default_path(self):
+        with patch.dict(os.environ, {}, clear=False):
+            os.environ.pop("HERMES_HOME", None)
+            home = get_hermes_home()
+            assert home == Path.home() / ".hermes"
+
+    def test_env_override(self):
+        with patch.dict(os.environ, {"HERMES_HOME": "/custom/path"}):
+            home = get_hermes_home()
+            assert home == Path("/custom/path")
+
+
+class TestEnsureHermesHome:
+    def test_creates_subdirs(self, tmp_path):
+        with patch.dict(os.environ, {"HERMES_HOME": str(tmp_path)}):
+            ensure_hermes_home()
+            assert (tmp_path / "cron").is_dir()
+            assert (tmp_path / "sessions").is_dir()
+            assert (tmp_path / "logs").is_dir()
+            assert (tmp_path / "memories").is_dir()
+
+
+class TestLoadConfigDefaults:
+    def test_returns_defaults_when_no_file(self, tmp_path):
+        with patch.dict(os.environ, {"HERMES_HOME": str(tmp_path)}):
+            config = load_config()
+            assert config["model"] == DEFAULT_CONFIG["model"]
+            assert config["max_turns"] == DEFAULT_CONFIG["max_turns"]
+            assert "terminal" in config
+            assert config["terminal"]["backend"] == "local"
+
+
+class TestSaveAndLoadRoundtrip:
+    def test_roundtrip(self, tmp_path):
+        with patch.dict(os.environ, {"HERMES_HOME": str(tmp_path)}):
+            config = load_config()
+            config["model"] = "test/custom-model"
+            config["max_turns"] = 42
+            save_config(config)
+
+            reloaded = load_config()
+            assert reloaded["model"] == "test/custom-model"
+            assert reloaded["max_turns"] == 42
+
+    def test_nested_values_preserved(self, tmp_path):
+        with patch.dict(os.environ, {"HERMES_HOME": str(tmp_path)}):
+            config = load_config()
+            config["terminal"]["timeout"] = 999
+            save_config(config)
+
+            reloaded = load_config()
+            assert reloaded["terminal"]["timeout"] == 999

tests/hermes_cli/test_models.py

@@ -0,0 +1,33 @@
+"""Tests for the hermes_cli models module."""
+
+from hermes_cli.models import OPENROUTER_MODELS, menu_labels, model_ids
+
+
+class TestModelIds:
+    def test_returns_strings(self):
+        ids = model_ids()
+        assert isinstance(ids, list)
+        assert len(ids) > 0
+        assert all(isinstance(mid, str) for mid in ids)
+
+    def test_ids_match_models_list(self):
+        ids = model_ids()
+        expected = [mid for mid, _ in OPENROUTER_MODELS]
+        assert ids == expected
+
+
+class TestMenuLabels:
+    def test_same_length_as_model_ids(self):
+        labels = menu_labels()
+        ids = model_ids()
+        assert len(labels) == len(ids)
+
+    def test_recommended_in_first(self):
+        labels = menu_labels()
+        assert "recommended" in labels[0].lower()
+
+    def test_labels_contain_model_ids(self):
+        labels = menu_labels()
+        ids = model_ids()
+        for label, mid in zip(labels, ids):
+            assert mid in label