feat(tui): render self-improvement review summaries in the transcript

The Ink TUI (\`hermes --tui\` + dashboard \`/chat\`) had no wiring for the
background self-improvement review. When the review fired and patched
a skill or saved a memory entry, the change landed but the user had
no visual indication it happened — only the CLI had a print surface
for the '💾 Self-improvement review: …' line.

Changes:

- tui_gateway/server.py: in _init_session, attach
  agent.background_review_callback to an _emit('review.summary',
  sid, {text}) closure. Wrapped in try/except so agents with locked
  attribute slots don't break session startup.
- ui-tui/src/app/createGatewayEventHandler.ts: handle 'review.summary'
  by routing ev.payload.text through sys(…), matching the existing
  'background.complete' pattern. Empty / whitespace payloads are
  ignored so the transcript never gets a blank system line.
- ui-tui/src/gatewayTypes.ts: extend the GatewayEvent discriminated
  union with { type: 'review.summary', payload?: { text?: string } }.

Gateway platforms (Telegram, Discord, Slack, …) already route the
review summary via background_review_callback → post-delivery queue
in gateway/run.py, so they pick up the new 'Self-improvement review:'
prefix from the companion run_agent change with no platform edits.

Tests:
- tests/tui_gateway/test_review_summary_callback.py (Python, 2 tests):
  _init_session attaches a callback that emits the right event; the
  callback path survives agents that can't accept the attribute.
- ui-tui/src/__tests__/createGatewayEventHandler.test.ts (vitest, 2
  new cases): review.summary events feed sys(...) with the full text;
  empty / missing payloads are no-ops.
- TypeScript type-check passes.
- tui_gateway suite: 64/64 pass.

tests/tui_gateway/test_review_summary_callback.py

@@ -0,0 +1,117 @@
+"""Tests for tui_gateway background-review summary delivery.
+
+When the self-improvement background review fires and saves a skill or
+memory entry, it calls ``agent.background_review_callback(message)``. In
+the CLI that routes through a prompt_toolkit-safe ``_cprint``; in the TUI
+there is no print surface, so without a callback wired up the review
+writes the change silently. ``_init_session`` attaches a callback that
+emits a ``review.summary`` event which Ink renders as a persistent
+transcript line.
+"""
+
+from __future__ import annotations
+
+import sys
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+
+@pytest.fixture()
+def server():
+    with patch.dict(
+        "sys.modules",
+        {
+            "hermes_constants": MagicMock(
+                get_hermes_home=MagicMock(return_value="/tmp/hermes_test_review_summary")
+            ),
+            "hermes_cli.env_loader": MagicMock(),
+            "hermes_cli.banner": MagicMock(),
+            "hermes_state": MagicMock(),
+        },
+    ):
+        import importlib
+
+        mod = importlib.import_module("tui_gateway.server")
+        yield mod
+        mod._sessions.clear()
+        mod._pending.clear()
+        mod._answers.clear()
+        mod._methods.clear()
+        importlib.reload(mod)
+
+
+def test_init_session_attaches_background_review_callback(server, monkeypatch):
+    """After _init_session, agent.background_review_callback is set to a
+    function that emits 'review.summary' for the session's sid."""
+    # Neutralize side-effect calls inside _init_session so we're testing
+    # just the callback wiring.
+    monkeypatch.setattr(server, "_SlashWorker", lambda *a, **kw: object())
+    monkeypatch.setattr(server, "_wire_callbacks", lambda sid: None)
+    monkeypatch.setattr(server, "_notify_session_boundary", lambda *a, **kw: None)
+    monkeypatch.setattr(server, "_session_info", lambda agent: {"model": "m"})
+    monkeypatch.setattr(server, "_load_show_reasoning", lambda: False)
+    monkeypatch.setattr(server, "_load_tool_progress_mode", lambda: "all")
+
+    captured_emits: list = []
+    monkeypatch.setattr(
+        server,
+        "_emit",
+        lambda event, sid, payload=None: captured_emits.append(
+            (event, sid, payload)
+        ),
+    )
+
+    class FakeAgent:
+        model = "fake/model"
+        # Presence of the attribute is all the Python side needs; the real
+        # AIAgent has it defaulted to None in __init__.
+        background_review_callback = None
+
+    agent = FakeAgent()
+    server._init_session("sid-abc", "session-key", agent, [], cols=80)
+
+    cb = getattr(agent, "background_review_callback", None)
+    assert callable(cb), (
+        "_init_session must attach a background_review_callback to the "
+        "agent so the self-improvement review is visible in the TUI."
+    )
+
+    # Clear the session.info emit captured during _init_session.
+    captured_emits.clear()
+
+    # Invoke the callback the way AIAgent._spawn_background_review would.
+    cb("💾 Self-improvement review: Skill 'hermes-release' patched")
+
+    # Exactly one review.summary event should have been emitted, bound to
+    # the session id we passed in, carrying the full message text.
+    matched = [e for e in captured_emits if e[0] == "review.summary"]
+    assert len(matched) == 1, captured_emits
+    event, sid, payload = matched[0]
+    assert sid == "sid-abc"
+    assert payload == {
+        "text": "💾 Self-improvement review: Skill 'hermes-release' patched"
+    }
+
+
+def test_review_summary_callback_survives_agent_without_attribute(server, monkeypatch):
+    """If the agent is a bare object that doesn't allow attribute
+    assignment (e.g. some stubbed test double), _init_session must not
+    raise — session startup stays robust."""
+    monkeypatch.setattr(server, "_SlashWorker", lambda *a, **kw: object())
+    monkeypatch.setattr(server, "_wire_callbacks", lambda sid: None)
+    monkeypatch.setattr(server, "_notify_session_boundary", lambda *a, **kw: None)
+    monkeypatch.setattr(server, "_session_info", lambda agent: {"model": "m"})
+    monkeypatch.setattr(server, "_load_show_reasoning", lambda: False)
+    monkeypatch.setattr(server, "_load_tool_progress_mode", lambda: "all")
+    monkeypatch.setattr(server, "_emit", lambda *a, **kw: None)
+
+    class LockedAgent:
+        __slots__ = ("model",)
+
+        def __init__(self):
+            self.model = "fake/model"
+
+    # LockedAgent's __slots__ blocks background_review_callback assignment.
+    server._init_session("sid-x", "key-x", LockedAgent(), [], cols=80)
+    # If we got here, _init_session swallowed the AttributeError gracefully.