AX Agent transcript 렌더 계획/적용 구조를 분리해 유지보수성을 높이고 문서를 갱신한다

- ChatWindow transcript 렌더를 planner/execution 단계로 분리해 RenderMessages 오케스트레이션을 단순화함
- TranscriptRenderPlanner/TranscriptRenderExecution partial을 추가해 planning과 host 적용 책임을 나눔
- README와 DEVELOPMENT 문서에 2026-04-09 09:37 (KST) 기준 구조 개선 이력을 반영함
- dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify\\ -p:IntermediateOutputPath=obj\\verify\\ 검증 결과 경고 0개 오류 0개

src/AxCopilot/Views/ChatWindow.TranscriptRenderExecution.cs

@@ -0,0 +1,60 @@
+namespace AxCopilot.Views;
+
+public partial class ChatWindow
+{
+    private bool TryApplyIncrementalTranscriptRender(TranscriptRenderPlan renderPlan)
+    {
+        if (!renderPlan.CanIncremental)
+            return false;
+
+        var prefixMatch = true;
+        for (var i = 0; i < renderPlan.PreviousStableCount; i++)
+        {
+            if (i >= renderPlan.NewKeys.Count || !string.Equals(_lastRenderedTimelineKeys[i], renderPlan.NewKeys[i], StringComparison.Ordinal))
+            {
+                prefixMatch = false;
+                break;
+            }
+        }
+
+        if (!prefixMatch)
+            return false;
+
+        try
+        {
+            for (var removeIndex = 0; removeIndex < renderPlan.PreviousLiveCount && GetTranscriptElementCount() > 0; removeIndex++)
+                RemoveTranscriptElementAt(GetTranscriptElementCount() - 1);
+
+            for (var i = renderPlan.PreviousStableCount; i < renderPlan.VisibleTimeline.Count; i++)
+                renderPlan.VisibleTimeline[i].Render();
+
+            _lastRenderedTimelineKeys = renderPlan.NewKeys;
+            _lastRenderedHiddenCount = renderPlan.HiddenCount;
+            return true;
+        }
+        catch (Exception ex)
+        {
+            Services.LogService.Warn($"증분 transcript 렌더 실패, 전체 렌더로 전환: {ex.Message}");
+            _lastRenderedTimelineKeys.Clear();
+            return false;
+        }
+    }
+
+    private void ApplyFullTranscriptRender(TranscriptRenderPlan renderPlan)
+    {
+        ClearTranscriptElements();
+        _runBannerAnchors.Clear();
+
+        if (renderPlan.HiddenCount > 0)
+            AddTranscriptElement(CreateTimelineLoadMoreCard(renderPlan.HiddenCount));
+
+        foreach (var item in renderPlan.VisibleTimeline)
+            item.Render();
+
+        if (_agentLiveContainer != null && !ContainsTranscriptElement(_agentLiveContainer))
+            AddTranscriptElement(_agentLiveContainer);
+
+        _lastRenderedTimelineKeys = renderPlan.NewKeys;
+        _lastRenderedHiddenCount = renderPlan.HiddenCount;
+    }
+}

src/AxCopilot/Views/ChatWindow.TranscriptRenderPlanner.cs

@@ -0,0 +1,65 @@
+using AxCopilot.Models;
+
+namespace AxCopilot.Views;
+
+public partial class ChatWindow
+{
+    private sealed class TranscriptRenderPlan
+    {
+        public required List<(string Key, DateTime Timestamp, int Order, Action Render)> VisibleTimeline { get; init; }
+        public required List<string> NewKeys { get; init; }
+        public required bool ShowHistory { get; init; }
+        public required int HiddenCount { get; init; }
+        public required bool CanIncremental { get; init; }
+        public required int PreviousLiveCount { get; init; }
+        public required int PreviousStableCount { get; init; }
+    }
+
+    private TranscriptRenderPlan BuildTranscriptRenderPlan(
+        ChatConversation conv,
+        IReadOnlyList<ChatMessage> visibleMessages,
+        IReadOnlyList<ChatExecutionEvent> visibleEvents)
+    {
+        var orderedTimeline = BuildTimelineRenderActions(visibleMessages, visibleEvents);
+        var effectiveRenderLimit = GetActiveTimelineRenderLimit();
+        var hiddenCount = Math.Max(0, orderedTimeline.Count - effectiveRenderLimit);
+        var visibleTimeline = hiddenCount > 0
+            ? orderedTimeline.GetRange(hiddenCount, orderedTimeline.Count - hiddenCount)
+            : orderedTimeline;
+
+        var newKeys = new List<string>(visibleTimeline.Count);
+        foreach (var item in visibleTimeline)
+            newKeys.Add(item.Key);
+
+        var hasExternalChildren = _agentLiveContainer != null && ContainsTranscriptElement(_agentLiveContainer);
+        var expectedChildCount = _lastRenderedTimelineKeys.Count + (_lastRenderedHiddenCount > 0 ? 1 : 0);
+        var canIncremental = !hasExternalChildren
+            && _lastRenderedTimelineKeys.Count > 0
+            && newKeys.Count >= _lastRenderedTimelineKeys.Count
+            && _lastRenderedHiddenCount == hiddenCount
+            && GetTranscriptElementCount() == expectedChildCount;
+
+        var previousLiveCount = 0;
+        if (canIncremental)
+        {
+            for (var i = _lastRenderedTimelineKeys.Count - 1; i >= 0; i--)
+            {
+                if (_lastRenderedTimelineKeys[i].StartsWith("_live_", StringComparison.Ordinal))
+                    previousLiveCount++;
+                else
+                    break;
+            }
+        }
+
+        return new TranscriptRenderPlan
+        {
+            VisibleTimeline = visibleTimeline,
+            NewKeys = newKeys,
+            ShowHistory = conv.ShowExecutionHistory,
+            HiddenCount = hiddenCount,
+            CanIncremental = canIncremental,
+            PreviousLiveCount = previousLiveCount,
+            PreviousStableCount = _lastRenderedTimelineKeys.Count - previousLiveCount,
+        };
+    }
+}

src/AxCopilot/Views/ChatWindow.TranscriptRendering.cs

@@ -1,6 +1,5 @@
 using System.Windows.Threading;
 using AxCopilot.Models;
-using AxCopilot.Services;
 
 namespace AxCopilot.Views;
 
@@ -58,96 +57,15 @@ public partial class ChatWindow
             InvalidateTimelineCache();
         }
 
-        var showHistory = conv.ShowExecutionHistory;
         EmptyState.Visibility = System.Windows.Visibility.Collapsed;
+        var renderPlan = BuildTranscriptRenderPlan(conv, visibleMessages, visibleEvents);
 
-        var orderedTimeline = BuildTimelineRenderActions(visibleMessages, visibleEvents);
-        var effectiveRenderLimit = GetActiveTimelineRenderLimit();
-        var hiddenCount = Math.Max(0, orderedTimeline.Count - effectiveRenderLimit);
-        var visibleTimeline = hiddenCount > 0
-            ? orderedTimeline.GetRange(hiddenCount, orderedTimeline.Count - hiddenCount)
-            : orderedTimeline;
-        var newKeys = new List<string>(visibleTimeline.Count);
-        foreach (var t in visibleTimeline)
-            newKeys.Add(t.Key);
+        if (!TryApplyIncrementalTranscriptRender(renderPlan))
+            ApplyFullTranscriptRender(renderPlan);
 
-        var incremented = false;
-        var hasExternalChildren = _agentLiveContainer != null && ContainsTranscriptElement(_agentLiveContainer);
-        var expectedChildCount = _lastRenderedTimelineKeys.Count + (_lastRenderedHiddenCount > 0 ? 1 : 0);
-        var canIncremental = !hasExternalChildren
-            && _lastRenderedTimelineKeys.Count > 0
-            && newKeys.Count >= _lastRenderedTimelineKeys.Count
-            && _lastRenderedHiddenCount == hiddenCount
-            && GetTranscriptElementCount() == expectedChildCount;
-
-        if (canIncremental)
-        {
-            var prevLiveCount = 0;
-            for (var i = _lastRenderedTimelineKeys.Count - 1; i >= 0; i--)
-            {
-                if (_lastRenderedTimelineKeys[i].StartsWith("_live_", StringComparison.Ordinal))
-                    prevLiveCount++;
-                else
-                    break;
-            }
-
-            var prevStableCount = _lastRenderedTimelineKeys.Count - prevLiveCount;
-            var prefixMatch = true;
-            for (var i = 0; i < prevStableCount; i++)
-            {
-                if (i >= newKeys.Count || !string.Equals(_lastRenderedTimelineKeys[i], newKeys[i], StringComparison.Ordinal))
-                {
-                    prefixMatch = false;
-                    break;
-                }
-            }
-
-            if (prefixMatch)
-            {
-                try
-                {
-                    for (var r = 0; r < prevLiveCount && GetTranscriptElementCount() > 0; r++)
-                        RemoveTranscriptElementAt(GetTranscriptElementCount() - 1);
-
-                    for (var i = prevStableCount; i < visibleTimeline.Count; i++)
-                        visibleTimeline[i].Render();
-
-                    _lastRenderedTimelineKeys = newKeys;
-                    _lastRenderedHiddenCount = hiddenCount;
-                    _lastRenderedMessageCount = visibleMessages.Count;
-                    _lastRenderedEventCount = visibleEvents.Count;
-                    _lastRenderedShowHistory = showHistory;
-                    incremented = true;
-                }
-                catch (Exception ex)
-                {
-                    LogService.Warn($"증분 렌더링 실패, 전체 재빌드로 전환: {ex.Message}");
-                    _lastRenderedTimelineKeys.Clear();
-                    incremented = false;
-                }
-            }
-        }
-
-        if (!incremented)
-        {
-            ClearTranscriptElements();
-            _runBannerAnchors.Clear();
-
-            if (hiddenCount > 0)
-                AddTranscriptElement(CreateTimelineLoadMoreCard(hiddenCount));
-
-            foreach (var item in visibleTimeline)
-                item.Render();
-
-            if (_agentLiveContainer != null && !ContainsTranscriptElement(_agentLiveContainer))
-                AddTranscriptElement(_agentLiveContainer);
-
-            _lastRenderedTimelineKeys = newKeys;
-            _lastRenderedHiddenCount = hiddenCount;
-            _lastRenderedMessageCount = visibleMessages.Count;
-            _lastRenderedEventCount = visibleEvents.Count;
-            _lastRenderedShowHistory = showHistory;
-        }
+        _lastRenderedMessageCount = visibleMessages.Count;
+        _lastRenderedEventCount = visibleEvents.Count;
+        _lastRenderedShowHistory = renderPlan.ShowHistory;
 
         if (!preserveViewport)
         {