test(config): cover enabled plugin toolset discovery during migration

tests/hermes_cli/test_config_plugin_toolsets.py

@@ -0,0 +1,42 @@
+"""Config migration recognizes enabled plugin toolsets discovered on demand."""
+
+import hermes_yaml as yaml
+
+from hermes_cli.config import DEFAULT_CONFIG, migrate_config
+
+
+class TestPlatformToolsetMigrationValidation:
+    def test_validation_discovers_enabled_plugin_toolsets(
+        self, tmp_path, monkeypatch
+    ):
+        plugin_dir = tmp_path / "plugins" / "late-bound-toolset"
+        plugin_dir.mkdir(parents=True)
+        (plugin_dir / "plugin.yaml").write_text(
+            "name: late-bound-toolset\n",
+            encoding="utf-8",
+        )
+        (plugin_dir / "__init__.py").write_text(
+            "def register(ctx):\n"
+            "    ctx.register_tool(\n"
+            "        name='late_bound_echo', toolset='late-bound-tools',\n"
+            "        schema={'name': 'late_bound_echo', 'description': 'Echo',\n"
+            "                'parameters': {'type': 'object', 'properties': {}}},\n"
+            "        handler=lambda args, **kw: '{}',\n"
+            "    )\n",
+            encoding="utf-8",
+        )
+        (tmp_path / "config.yaml").write_text(
+            yaml.safe_dump(
+                {
+                    "_config_version": DEFAULT_CONFIG["_config_version"],
+                    "platform_toolsets": {"cli": ["late-bound-tools", "unknown-tools"]},
+                    "plugins": {"enabled": ["late-bound-toolset"]},
+                }
+            ),
+            encoding="utf-8",
+        )
+        monkeypatch.setenv("HERMES_HOME", str(tmp_path))
+
+        results = migrate_config(interactive=False, quiet=True)
+        assert not any("late-bound-tools" in w for w in results["warnings"])
+        assert any("unknown-tools" in w for w in results["warnings"])