fix: markdown渲染优化；socket关闭异常处理

AgentTest/AgentEngineLogicTests.cs

 using Newtonsoft.Json.Linq;
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using Tools.MyAgent;
 using Tools.MyAgent.Agent;
+using Tools.MyAgent.Kb;
 
 namespace AgentTest
 {
@@ -11,6 +13,20 @@ namespace AgentTest
     /// </summary>
     public sealed class AgentEngineLogicTests : TestRunner
     {
+        [Test]
+        public void Dispose_PreventsLateRunAndIsIdempotent()
+        {
+            var engine = new AgentEngine(new KbService());
+            int errorCount = 0;
+            engine.OnError += _ => errorCount++;
+
+            engine.Dispose();
+            engine.Dispose();
+            engine.RunAsync(new List<ChatMessage>(), CancellationToken.None).GetAwaiter().GetResult();
+
+            Assert.Equal(0, errorCount, "释放后的迟到请求不应再向 UI 上报网络错误");
+        }
+
         // ── token 估算 ──
 
         [Test]

AgentTest/MarkdownRendererTests.cs

@@ -32,6 +32,26 @@ namespace AgentTest
             Assert.Contains(rtf, @"\u26041?\u27861?\u-29766?", "正文缺失");
         }
 
+        [Test]
+        public void ThinkingMarker_UsesFontSafeText()
+        {
+            string rtf = MarkdownRenderer.BuildChatRtf(
+                new List<ChatMessage>
+                {
+                    new ChatMessage
+                    {
+                        Role = "assistant",
+                        ThinkingContent = "正在分析",
+                        Content = "回答",
+                        Timestamp = DateTime.Now,
+                    }
+                },
+                null);
+
+            Assert.Contains(rtf, "> Thinking...", "thinking 标记应使用可稳定渲染的文本");
+            Assert.NotContains(rtf, @"{\f2 \u9656?}", "thinking 标记不应切换到缺少字形的 Emoji 字体");
+        }
+
         [Test]
         public void OrderedList_StillRendered()
         {

Tools.Agent/Agent/AgentEngine.cs

@@ -26,6 +26,7 @@ namespace Tools.MyAgent.Agent
         private readonly DialectService _dialect;   // 内置方言/行业知识（程序目录 Agent/dialect + Agent/industry）
         private AgentProductContext _productContext;
         private CancellationTokenSource _cts;
+        private int _disposeStarted;
 
         /// <summary>上下文 token 预算（由配置注入；默认 32000）</summary>
         private int _contextTokens = 32000;
@@ -72,6 +73,8 @@ namespace Tools.MyAgent.Agent
 
         public bool IsRunning { get; private set; }
 
+        private bool IsDisposed => Volatile.Read(ref _disposeStarted) != 0;
+
         /// <summary>本会话累计 prompt tokens（D16 用量统计；由 SendAndLogAsync 累加，NewChat 时重置）</summary>
         public int TotalPromptTokens { get; private set; }
 
@@ -235,7 +238,7 @@ namespace Tools.MyAgent.Agent
         /// </summary>
         public async Task RunAsync(IReadOnlyList<ChatMessage> history, CancellationToken ct)
         {
-            if (IsRunning) return;
+            if (IsDisposed || IsRunning) return;
             IsRunning = true;
             _cts = CancellationTokenSource.CreateLinkedTokenSource(ct);
             OnStatusChanged?.Invoke();
@@ -325,16 +328,21 @@ namespace Tools.MyAgent.Agent
                     }
                 }
 
+                if (!IsDisposed)
+                {
                     OnComplete?.Invoke();
                     if (_toolTrace.Count > 0)
                         OnToolTrace?.Invoke(_toolTrace.ToArray());
                 }
+            }
             catch (OperationCanceledException)
             {
+                if (!IsDisposed)
                     OnError?.Invoke("已取消。");
             }
             catch (Exception ex)
             {
+                if (!IsDisposed)
                     OnError?.Invoke(DescribeError(ex));
             }
             finally
@@ -342,6 +350,7 @@ namespace Tools.MyAgent.Agent
                 IsRunning = false;
                 try { _cts?.Dispose(); } catch { }
                 _cts = null;
+                if (!IsDisposed)
                     OnStatusChanged?.Invoke();
             }
         }
@@ -1072,6 +1081,7 @@ namespace Tools.MyAgent.Agent
 
         public void Dispose()
         {
+            if (Interlocked.Exchange(ref _disposeStarted, 1) != 0) return;
             Cancel();
             try { _client.Dispose(); } catch { }
             try { _backupClient?.Dispose(); } catch { }

Tools.Agent/Kb/KbIndex.cs

@@ -77,26 +77,43 @@ namespace Tools.MyAgent.Kb
             _emb = emb;
         }
 
-        /// <summary>启动：打开/建库 + 后台构建（幂等）</summary>
+        /// <summary>启动索引：只在后台打开 SQLite 并开始构建，调用方不会被建库 IO 阻塞。</summary>
         public void Start()
         {
             lock (_lock)
             {
                 if (_started) return;
                 _started = true;
+            }
+            Task.Run(StartCore);
+        }
+
+        private void StartCore()
+        {
             try
             {
+                _cts.Token.ThrowIfCancellationRequested();
+                lock (_lock)
+                {
+                    if (_cts.IsCancellationRequested) return;
                     OpenDb();
                 }
+                if (_cts.IsCancellationRequested || _conn == null) return;
+                _sweepTimer = new Timer(_ => Invalidate(), null, SweepInterval, SweepInterval);
+                Invalidate();
+            }
+            catch (OperationCanceledException)
+            {
+                // 关闭窗口时取消尚未完成的后台初始化。
+            }
             catch (Exception ex)
+            {
+                lock (_lock)
                 {
                     _conn = null;
-                    OnStatus?.Invoke("索引不可用：" + ex.Message);
-                    return;
                 }
+                OnStatus?.Invoke("索引不可用：" + ex.Message);
             }
-            _sweepTimer = new Timer(_ => Invalidate(), null, SweepInterval, SweepInterval);
-            Invalidate();
         }
 
         /// <summary>标记变更，调度后台增量重建（带去抖；构建中则完成后自动续跑）</summary>

Tools.Agent/Kb/KbService.cs

@@ -410,6 +410,19 @@ namespace Tools.MyAgent.Kb
         /// <summary>搜索范围是否有效（目录存在）</summary>
         public bool IsSearchValid => !string.IsNullOrEmpty(SearchRoot) && Directory.Exists(SearchRoot);
 
+        private const int AutoIndexFileThreshold = 2000;
+
+        /// <summary>
+        /// 仅为小型知识库自动启动索引。文件数未知或超过阈值时保持未建索引，避免打开窗口触发大规模 SQLite 建库。
+        /// </summary>
+        public void EnsureIndexStartedIfSmall(int maxFiles = AutoIndexFileThreshold)
+        {
+            if (maxFiles < 1) return;
+            int count = FileCount;
+            if (count < 0 || count > maxFiles) return;
+            EnsureIndexStarted();
+        }
+
         /// <summary>
         /// 启动后台检索索引（幂等）：索引目录固定为输出目录下 index 文件夹，与所选知识库无关。
         /// <para>索引覆盖整个知识库根目录；搜索范围限定时在查询侧过滤，索引本身始终按根目录构建。</para>

Tools.Agent/Support/MarkdownRenderer.cs

@@ -145,8 +145,7 @@ namespace Tools.MyAgent
                 {
                     sb.Append(@"\cf"); sb.Append(ClThinking);
                     sb.Append(@"\i\fs18 ");
-                    sb.Append(EscapeChar('▸'));
-                    sb.Append(" Thinking...");
+                    sb.Append("> Thinking...");
                     sb.Append(@"\par ");
                     sb.Append(Escape(msg.ThinkingContent));
                     sb.Append(@"\i0\fs20\cf"); sb.Append(ClText);

Tools.Agent/wMyAgent.Designer.cs

@@ -208,7 +208,7 @@ namespace Tools.MyAgent
             // 
             this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 17F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
-            this.ClientSize = new System.Drawing.Size(817, 638);
+            this.ClientSize = new System.Drawing.Size(1000, 600);
             this.Controls.Add(this.panelChat);
             this.Controls.Add(this.panelToolbar);
             this.Controls.Add(this.panelBottom);
@@ -216,6 +216,7 @@ namespace Tools.MyAgent
             this.KeyPreview = true;
             this.Margin = new System.Windows.Forms.Padding(5, 6, 5, 6);
             this.Name = "wMyAgent";
+            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
             this.Text = "智能助手";
             this.panelBottom.ResumeLayout(false);
             this.panelBottom.PerformLayout();

Tools.Agent/wMyAgent.cs

@@ -29,6 +29,8 @@ namespace Tools.MyAgent
         private RichTextBox _rtfFallback;
         private AgentConfig _config = new AgentConfig();
         private CancellationTokenSource _sendCts;
+        private volatile bool _isClosing;
+        private int _disposeStarted;
         private string _historyDir;
         private bool _sessionSaved;
         /// <summary>v2.3 待发送附图列表：粘贴截图后暂存，随下一轮提问发送（启用图片提问时；最多 5 张）</summary>
@@ -143,6 +145,8 @@ namespace Tools.MyAgent
         /// </summary>
         partial void OnFormDisposing()
         {
+            if (Interlocked.Exchange(ref _disposeStarted, 1) != 0) return;
+            _isClosing = true;
             SaveUnsavedSession();
             try { _cmdNameFont?.Dispose(); } catch { }
             try { _cmdDescFont?.Dispose(); } catch { }
@@ -339,7 +343,8 @@ namespace Tools.MyAgent
             _kb.SetOutputRoot(DefaultKbRoot);
             // 评估#1：存储自动清理（日志 30 天 / 中间产物 7~30 天 / 正式产出 90 天；后台执行不阻塞启动）
             try { System.Threading.Tasks.Task.Run(() => StorageCleanup.Run(DefaultKbRoot)); } catch { }
-            _kb.EnsureIndexStarted();   // 后台构建知识库检索索引（含 docx/xlsx 内容），检索提速
+            // 大知识库不在窗口初始化阶段创建 SQLite 索引，避免打开业务引用时被 IO/SQLite 锁住。
+            // 小知识库由统计完成事件按需后台启动，实际搜索也会触发惰性启动。
             RefreshScopeCombo();   // 先归一化搜索范围（命中下拉项/归一化为全部），再应用
             _kb.SetScope(_config.SearchScope);
             _historyDir = HistoryManager.EnsureHistoryDir(WorkingDirForHistory());
@@ -353,6 +358,28 @@ namespace Tools.MyAgent
 
         // ── 事件绑定 ─────────────────────────────────────
 
+        private void PostToUi(Action action)
+        {
+            if (action == null || _isClosing || IsDisposed || Disposing || !IsHandleCreated) return;
+            if (!InvokeRequired)
+            {
+                if (_isClosing || IsDisposed || Disposing) return;
+                action();
+                return;
+            }
+
+            try
+            {
+                BeginInvoke((MethodInvoker)delegate
+                {
+                    if (_isClosing || IsDisposed || Disposing) return;
+                    action();
+                });
+            }
+            catch (ObjectDisposedException) { }
+            catch (InvalidOperationException) { }
+        }
+
         private void WireEvents()
         {
             lblNewChat.LinkClicked += (s, e) => NewChat();
@@ -371,25 +398,30 @@ namespace Tools.MyAgent
             // RichBox 模式的点击/悬停交互（路径点击、details 折叠切换）
             WireRtfEvents();
 
-            _engine.OnTextDelta += t => this.AsyncUI(() => OnAssistantTextDelta(t));
-            _engine.OnThinkingDelta += t => this.AsyncUI(() => OnAssistantThinkingDelta(t));
-            _engine.OnToolStatus += s => this.AsyncUI(() => OnToolStatusChanged(s));
-            _engine.OnFileProduced += f => this.AsyncUI(() => OnFileProduced(f));
-            _engine.OnComplete += () => this.AsyncUI(OnAssistantComplete);
-            _engine.OnToolTrace += trace => this.AsyncUI(() => OnToolTrace(trace));
-            _engine.OnError += m => this.AsyncUI(() => OnEngineError(m));
-            _engine.OnStatusChanged += () => this.AsyncUI(UpdateStatusIndicator);
+            _engine.OnTextDelta += t => PostToUi(() => OnAssistantTextDelta(t));
+            _engine.OnThinkingDelta += t => PostToUi(() => OnAssistantThinkingDelta(t));
+            _engine.OnToolStatus += s => PostToUi(() => OnToolStatusChanged(s));
+            _engine.OnFileProduced += f => PostToUi(() => OnFileProduced(f));
+            _engine.OnComplete += () => PostToUi(OnAssistantComplete);
+            _engine.OnToolTrace += trace => PostToUi(() => OnToolTrace(trace));
+            _engine.OnError += m => PostToUi(() => OnEngineError(m));
+            _engine.OnStatusChanged += () => PostToUi(UpdateStatusIndicator);
             // 知识库文件数后台统计完成 → 回刷状态栏与欢迎语（窗体句柄未就绪时跳过，Load 时会重新触发）
-            _kb.StatsRefreshed += () => this.AsyncUI(() =>
+            _kb.StatsRefreshed += () =>
+            {
+                _kb.EnsureIndexStartedIfSmall();
+                PostToUi(() =>
                 {
                     if (!IsHandleCreated) return;
                     UpdateStatusIndicator();
                     RefreshChat();
                 });
+            };
 
             FormClosing += (s, e) =>
             {
-                SaveCurrentSession();
+                _isClosing = true;
+                SaveUnsavedSession();
             };
 
             Load += (s, e) =>
@@ -686,6 +718,7 @@ namespace Tools.MyAgent
 
         private void OnEngineError(string message)
         {
+            if (_isClosing || IsDisposed || Disposing) return;
             var last = LastAssistantMessage();
             if (last != null && last.IsStreaming)
             {
@@ -2277,16 +2310,26 @@ namespace Tools.MyAgent
         }
 
         /// <summary>/kb <关键词>：直接检索知识库并展示结果</summary>
-        private void RunKbQuickSearch(string keyword)
+        private async void RunKbQuickSearch(string keyword)
+        {
+            var sw = System.Diagnostics.Stopwatch.StartNew();
+            string result;
+            try
+            {
+                result = await Task.Run(() =>
                 {
                     if (!_kb.ConnectIfNeeded() || !_kb.IsSearchValid)
+                        return "知识库不可用（目录不存在/共享未连接），请先选择知识库。";
+
+                    // 首次实际检索才惰性启动索引；大知识库的无索引回退扫描也不占用 UI 线程。
+                    _kb.EnsureIndexStarted();
+                    return _kb.Grep(keyword, null, 10);
+                });
+            }
+            catch (Exception ex)
             {
-                AddSystemMessage("知识库不可用（目录不存在/共享未连接），请先选择知识库。");
-                return;
+                result = "知识库检索失败：" + ex.Message;
             }
-            _kb.EnsureIndexStarted();
-            var sw = System.Diagnostics.Stopwatch.StartNew();
-            string result = _kb.Grep(keyword, null, 10);
             sw.Stop();
             AddSystemMessage($"**知识库检索：{keyword}**（{sw.ElapsedMilliseconds}ms）\n\n{result}");
         }