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.

tui_gateway/server.py

@@ -1806,6 +1806,21 @@ def _init_session(sid: str, key: str, agent, history: list, cols: int = 80):
         load_permanent_allowlist()
     except Exception:
         pass
+    # Surface the self-improvement background review's "💾 …" summary as a
+    # review.summary event so Ink can render it as a persistent system line
+    # in the transcript. In the CLI path this message is printed via
+    # prompt_toolkit; the TUI has no equivalent print surface, so without
+    # this callback the review would write the skill/memory change silently.
+    try:
+        agent.background_review_callback = (
+            lambda message, _sid=sid: _emit(
+                "review.summary", _sid, {"text": str(message)}
+            )
+        )
+    except Exception:
+        # Bare AIAgents that don't expose the attribute (unlikely, but keep
+        # session startup resilient).
+        pass
     _wire_callbacks(sid)
     _notify_session_boundary("on_session_reset", key)
     _emit("session.info", sid, _session_info(agent))