feat(webui): polish chat layout and titles

Align the WebUI sidebar and chat chrome with the updated design, and generate WebUI session titles asynchronously without blocking turns.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/agent/test_loop_progress.py

@@ -1,5 +1,6 @@
 """Tests for structured tool-event progress metadata emitted by AgentLoop."""
 
+import asyncio
 from pathlib import Path
 from unittest.mock import AsyncMock, MagicMock
 
@@ -291,6 +292,48 @@ class TestToolEventProgress:
         assert (outbound[-1].metadata or {}).get("_turn_end") is True
         assert outbound[-1].chat_id == "chat1"
 
+    @pytest.mark.asyncio
+    async def test_webui_title_generation_runs_after_turn_end(self, tmp_path: Path) -> None:
+        bus = MessageBus()
+        provider = MagicMock()
+        provider.get_default_model.return_value = "test-model"
+        title_started = asyncio.Event()
+        release_title = asyncio.Event()
+        calls = 0
+
+        async def chat_with_retry(*_args: object, **_kwargs: object) -> LLMResponse:
+            nonlocal calls
+            calls += 1
+            if calls == 1:
+                return LLMResponse(content="Done", tool_calls=[])
+            title_started.set()
+            await release_title.wait()
+            return LLMResponse(content="Generated title", tool_calls=[])
+
+        provider.chat_with_retry = AsyncMock(side_effect=chat_with_retry)
+        loop = AgentLoop(bus=bus, provider=provider, workspace=tmp_path, model="test-model")
+        loop.tools.get_definitions = MagicMock(return_value=[])
+        loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
+
+        await asyncio.wait_for(loop._dispatch(InboundMessage(
+            channel="websocket",
+            sender_id="u1",
+            chat_id="chat1",
+            content="say hello",
+            metadata={"webui": True},
+        )), timeout=0.5)
+
+        outbound = [await bus.consume_outbound(), await bus.consume_outbound()]
+        assert outbound[0].content == "Done"
+        assert (outbound[1].metadata or {}).get("_turn_end") is True
+
+        await asyncio.wait_for(title_started.wait(), timeout=0.5)
+        release_title.set()
+        session_updated = await asyncio.wait_for(bus.consume_outbound(), timeout=0.5)
+
+        assert (session_updated.metadata or {}).get("_session_updated") is True
+        assert provider.chat_with_retry.await_count == 2
+
     @pytest.mark.asyncio
     async def test_non_websocket_dispatch_does_not_publish_turn_end_marker(self, tmp_path: Path) -> None:
         bus = MessageBus()

tests/agent/test_loop_save_turn.py

@@ -8,7 +8,13 @@ from nanobot.agent.context import ContextBuilder
 from nanobot.agent.loop import AgentLoop
 from nanobot.bus.events import InboundMessage
 from nanobot.bus.queue import MessageBus
+from nanobot.providers.base import LLMResponse
 from nanobot.session.manager import Session
+from nanobot.utils.webui_titles import (
+    WEBUI_SESSION_METADATA_KEY,
+    WEBUI_TITLE_METADATA_KEY,
+    maybe_generate_webui_title,
+)
 
 
 def _mk_loop() -> AgentLoop:
@@ -22,9 +28,56 @@ def _mk_loop() -> AgentLoop:
 def _make_full_loop(tmp_path: Path) -> AgentLoop:
     provider = MagicMock()
     provider.get_default_model.return_value = "test-model"
+    provider.chat_with_retry = AsyncMock(return_value=LLMResponse(content="Test title"))
     return AgentLoop(bus=MessageBus(), provider=provider, workspace=tmp_path, model="test-model")
 
 
+@pytest.mark.asyncio
+async def test_generate_webui_title_only_for_marked_webui_sessions(tmp_path: Path) -> None:
+    loop = _make_full_loop(tmp_path)
+    loop.provider.chat_with_retry = AsyncMock(
+        return_value=LLMResponse(content='"优化 WebUI 侧边栏。"', finish_reason="stop")
+    )
+    session = loop.sessions.get_or_create("websocket:chat-title")
+    session.metadata[WEBUI_SESSION_METADATA_KEY] = True
+    session.add_message("user", "帮我优化一下 webui 的 sidebar")
+    session.add_message("assistant", "可以，我会先调整布局和视觉层级。")
+    loop.sessions.save(session)
+
+    generated = await maybe_generate_webui_title(
+        sessions=loop.sessions,
+        session_key="websocket:chat-title",
+        provider=loop.provider,
+        model=loop.model,
+    )
+
+    assert generated is True
+    assert session.metadata[WEBUI_TITLE_METADATA_KEY] == "优化 WebUI 侧边栏"
+    loop.provider.chat_with_retry.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_generate_webui_title_skips_plain_websocket_sessions(tmp_path: Path) -> None:
+    loop = _make_full_loop(tmp_path)
+    loop.provider.chat_with_retry = AsyncMock(
+        return_value=LLMResponse(content="Plain websocket title", finish_reason="stop")
+    )
+    session = loop.sessions.get_or_create("websocket:custom-client")
+    session.add_message("user", "hello from a custom websocket client")
+    loop.sessions.save(session)
+
+    generated = await maybe_generate_webui_title(
+        sessions=loop.sessions,
+        session_key="websocket:custom-client",
+        provider=loop.provider,
+        model=loop.model,
+    )
+
+    assert generated is False
+    assert WEBUI_TITLE_METADATA_KEY not in session.metadata
+    loop.provider.chat_with_retry.assert_not_awaited()
+
+
 def test_save_turn_skips_multimodal_user_when_only_runtime_context() -> None:
     loop = _mk_loop()
     session = Session(key="test:runtime-only")

tests/agent/test_session_manager_history.py

@@ -1,4 +1,4 @@
-from nanobot.session.manager import Session
+from nanobot.session.manager import Session, SessionManager
 
 
 def _assert_no_orphans(history: list[dict]) -> None:
@@ -31,6 +31,18 @@ def _tool_turn(prefix: str, idx: int) -> list[dict]:
     ]
 
 
+def test_list_sessions_includes_metadata_title(tmp_path):
+    manager = SessionManager(tmp_path)
+    session = manager.get_or_create("websocket:chat-title")
+    session.metadata["title"] = "自动生成标题"
+    manager.save(session)
+
+    rows = manager.list_sessions()
+
+    assert rows[0]["key"] == "websocket:chat-title"
+    assert rows[0]["title"] == "自动生成标题"
+
+
 # --- Original regression test (from PR 2075) ---
 
 def test_get_history_drops_orphan_tool_results_when_window_cuts_tool_calls():