test+docs: cover transform_llm_output hook + release author map

- tests/test_transform_llm_output_hook.py: dispatch semantics
  (kwargs contract, first-non-empty-string-wins, empty-string
  pass-through, raising-plugin fail-open, no-plugins = no-op)
- tests/hermes_cli/test_plugins.py: assert the new hook name is in
  VALID_HOOKS alongside the other transform_* hooks
- website/docs/user-guide/features/hooks.md: summary-table entry +
  full section mirroring transform_tool_result / transform_terminal_output
- scripts/release.py: map barnacleboy.jezzahehn@agentmail.to -> JezzaHehn
  (existing entry only covers the gmail address)

tests/hermes_cli/test_plugins.py

@@ -330,6 +330,7 @@ class TestPluginHooks:
         assert "post_api_request" in VALID_HOOKS
         assert "transform_terminal_output" in VALID_HOOKS
         assert "transform_tool_result" in VALID_HOOKS
+        assert "transform_llm_output" in VALID_HOOKS
 
     def test_valid_hooks_include_pre_gateway_dispatch(self):
         assert "pre_gateway_dispatch" in VALID_HOOKS

tests/test_transform_llm_output_hook.py

@@ -0,0 +1,159 @@
+"""Tests for the ``transform_llm_output`` plugin hook.
+
+The hook fires inside ``AIAgent.run_conversation`` once the tool-calling
+loop has produced a final response. Driving the full agent loop from a
+unit test would be prohibitively heavy, so these tests exercise the
+invoke_hook dispatch semantics that the wiring in ``run_agent.py``
+depends on:
+
+    for _hook_result in _transform_results:
+        if isinstance(_hook_result, str) and _hook_result:
+            final_response = _hook_result
+            break  # First non-empty string wins
+
+Mirrors ``test_transform_tool_result_hook.py`` which tests the equivalent
+contract for the generic tool-result seam.
+"""
+
+from pathlib import Path
+
+import yaml
+
+import hermes_cli.plugins as plugins_mod
+from hermes_cli.plugins import PluginManager, VALID_HOOKS
+
+
+def _make_enabled_plugin(hermes_home: Path, name: str, register_body: str) -> Path:
+    """Create a plugin under <hermes_home>/plugins/<name> and opt it in."""
+    plugin_dir = hermes_home / "plugins" / name
+    plugin_dir.mkdir(parents=True)
+    (plugin_dir / "plugin.yaml").write_text(
+        yaml.safe_dump({"name": name, "version": "0.1.0"}), encoding="utf-8",
+    )
+    (plugin_dir / "__init__.py").write_text(
+        "def register(ctx):\n"
+        f"    {register_body}\n",
+        encoding="utf-8",
+    )
+    cfg_path = hermes_home / "config.yaml"
+    cfg = {}
+    if cfg_path.exists():
+        cfg = yaml.safe_load(cfg_path.read_text()) or {}
+    cfg.setdefault("plugins", {}).setdefault("enabled", []).append(name)
+    cfg_path.write_text(yaml.safe_dump(cfg), encoding="utf-8")
+    return plugin_dir
+
+
+def test_transform_llm_output_in_valid_hooks():
+    assert "transform_llm_output" in VALID_HOOKS
+
+
+def test_hook_receives_expected_kwargs(tmp_path, monkeypatch):
+    """Hook callback should see response_text + session_id + model + platform."""
+    hermes_home = tmp_path / "hermes_test"
+    hermes_home.mkdir(exist_ok=True)
+    _make_enabled_plugin(
+        hermes_home, "capture_hook",
+        register_body=(
+            'ctx.register_hook("transform_llm_output", '
+            'lambda **kw: f"{kw[\'response_text\']}|{kw[\'session_id\']}|'
+            '{kw[\'model\']}|{kw[\'platform\']}")'
+        ),
+    )
+    monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+    mgr = PluginManager()
+    mgr.discover_and_load()
+
+    results = mgr.invoke_hook(
+        "transform_llm_output",
+        response_text="hello world",
+        session_id="s1",
+        model="anthropic/claude-sonnet-4.6",
+        platform="cli",
+    )
+    assert results == ["hello world|s1|anthropic/claude-sonnet-4.6|cli"]
+
+
+def test_first_non_empty_string_wins_semantics():
+    """Simulate the run_agent.py loop: first non-empty string replaces text."""
+    # The dispatch contract: invoke_hook returns a list; the caller walks
+    # it and stops at the first isinstance(_, str) and _.
+    hook_returns = [None, "", {"bad": True}, 123, "first-winner", "second"]
+
+    final_response = "original"
+    for _hook_result in hook_returns:
+        if isinstance(_hook_result, str) and _hook_result:
+            final_response = _hook_result
+            break
+
+    assert final_response == "first-winner"
+
+
+def test_empty_string_return_leaves_response_unchanged():
+    """Empty string must not replace the response (pass-through signal)."""
+    hook_returns = [""]
+
+    final_response = "original"
+    for _hook_result in hook_returns:
+        if isinstance(_hook_result, str) and _hook_result:
+            final_response = _hook_result
+            break
+
+    assert final_response == "original"
+
+
+def test_hook_exception_does_not_replace_response(tmp_path, monkeypatch):
+    """A plugin raising an exception must not break hook dispatch.
+
+    PluginManager.invoke_hook catches per-callback exceptions, logs a
+    warning, and continues — so a raising plugin contributes no entry
+    to the results list, and the walk in run_agent.py finds nothing to
+    replace with.
+    """
+    hermes_home = tmp_path / "hermes_test"
+    hermes_home.mkdir(exist_ok=True)
+    _make_enabled_plugin(
+        hermes_home, "raising_hook",
+        register_body=(
+            'def _boom(**kw):\n'
+            '        raise RuntimeError("boom")\n'
+            '    ctx.register_hook("transform_llm_output", _boom)'
+        ),
+    )
+    monkeypatch.setenv("HERMES_HOME", str(hermes_home))
+
+    mgr = PluginManager()
+    mgr.discover_and_load()
+
+    results = mgr.invoke_hook(
+        "transform_llm_output",
+        response_text="keep me",
+        session_id="s1",
+        model="m",
+        platform="cli",
+    )
+
+    final_response = "keep me"
+    for _hook_result in results:
+        if isinstance(_hook_result, str) and _hook_result:
+            final_response = _hook_result
+            break
+
+    assert final_response == "keep me"
+
+
+def test_no_plugins_returns_empty_results(tmp_path, monkeypatch):
+    """With no plugins loaded, invoke_hook returns [] and the response is unchanged."""
+    monkeypatch.setenv("HERMES_HOME", str(tmp_path / "hermes_empty"))
+    plugins_mod._plugin_manager = PluginManager()
+
+    mgr = plugins_mod._plugin_manager
+    results = mgr.invoke_hook(
+        "transform_llm_output",
+        response_text="unchanged",
+        session_id="",
+        model="m",
+        platform="",
+    )
+    assert results == []