컨텍스트 압축 계층 확장과 세션 누적 계측 보강

- claude-code compact 흐름을 참고해 AX에 session memory compact, microcompact, collapse/snip 단계를 추가하고 ContextCondenser를 단계별 결과 반환 구조로 확장함

- ChatConversation과 AX Agent 하단 컨텍스트 카드에 대화별 compact 누적 회수, 절감 토큰, session memory/microcompact/snip 집계를 반영함

- AGENTS.md에 개발 단계부터 최적화와 실행 속도를 우선 고려하는 작업 지침을 추가함

- 검증: dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify\\ -p:IntermediateOutputPath=obj\\verify\\ (경고 0 / 오류 0)

src/AxCopilot/Views/ChatWindow.xaml.cs

@@ -99,6 +99,14 @@ public partial class ChatWindow : Window
     private int? _lastCompactionAfterTokens;
     private DateTime? _lastCompactionAt;
     private bool _lastCompactionWasAutomatic;
+    private string _lastCompactionStageSummary = "";
+    private int _sessionCompactionCount;
+    private int _sessionAutomaticCompactionCount;
+    private int _sessionManualCompactionCount;
+    private int _sessionCompactionSavedTokens;
+    private int _sessionMemoryCompactionCount;
+    private int _sessionMicrocompactBoundaryCount;
+    private int _sessionSnipCompactionCount;
     private void ApplyQuickActionVisual(Button button, bool active, string activeBg, string activeFg)
     {
         if (button?.Content is not string text)
@@ -1686,6 +1694,7 @@ public partial class ChatWindow : Window
         }
         // 대화별 설정 복원 (없으면 전역 기본값)
         LoadConversationSettings();
+        LoadCompactionMetricsFromConversation();
         UpdatePermissionUI();
         UpdateDataUsageUI();
         RefreshContextUsageVisual();
@@ -1711,6 +1720,25 @@ public partial class ChatWindow : Window
         _selectedMood = conv?.Mood ?? llm.DefaultMood ?? "modern";
     }
 
+    private void LoadCompactionMetricsFromConversation()
+    {
+        ChatConversation? conv;
+        lock (_convLock) conv = _currentConversation;
+
+        _sessionCompactionCount = conv?.CompactionCount ?? 0;
+        _sessionAutomaticCompactionCount = conv?.AutomaticCompactionCount ?? 0;
+        _sessionManualCompactionCount = conv?.ManualCompactionCount ?? 0;
+        _sessionCompactionSavedTokens = conv?.CompactionSavedTokens ?? 0;
+        _sessionMemoryCompactionCount = conv?.SessionMemoryCompactionCount ?? 0;
+        _sessionMicrocompactBoundaryCount = conv?.MicrocompactBoundaryCount ?? 0;
+        _sessionSnipCompactionCount = conv?.SnipCompactionCount ?? 0;
+        _lastCompactionAt = conv?.LastCompactionAt;
+        _lastCompactionWasAutomatic = conv?.LastCompactionWasAutomatic ?? false;
+        _lastCompactionBeforeTokens = conv?.LastCompactionBeforeTokens;
+        _lastCompactionAfterTokens = conv?.LastCompactionAfterTokens;
+        _lastCompactionStageSummary = conv?.LastCompactionStageSummary ?? "";
+    }
+
     /// <summary>현재 하단 바 설정을 대화에 저장합니다.</summary>
     private void SaveConversationSettings()
     {
@@ -6500,9 +6528,8 @@ public partial class ChatWindow : Window
         ForceScrollToEnd();
 
         var llm = _settings.Settings.Llm;
-        var beforeTokens = Services.TokenEstimator.EstimateMessages(conv.Messages);
         var working = conv.Messages.ToList();
-        var condensed = await ContextCondenser.CondenseIfNeededAsync(
+        var compactResult = await ContextCondenser.CondenseWithStatsAsync(
             working,
             _llm,
             llm.MaxContextTokens,
@@ -6510,10 +6537,11 @@ public partial class ChatWindow : Window
             llm.ContextCompactTriggerPercent,
             true,
             CancellationToken.None);
-        var afterTokens = Services.TokenEstimator.EstimateMessages(working);
-        RecordCompactionStats(beforeTokens, afterTokens, wasAutomatic: false);
+        var beforeTokens = compactResult.BeforeTokens;
+        var afterTokens = compactResult.AfterTokens;
+        RecordCompactionStats(compactResult, wasAutomatic: false);
 
-        if (condensed)
+        if (compactResult.Changed)
         {
             lock (_convLock)
             {
@@ -6521,8 +6549,8 @@ public partial class ChatWindow : Window
             }
         }
 
-        var assistantText = condensed
-            ? $"컨텍스트 압축을 수행했습니다. 입력 토큰 추정치: {beforeTokens:N0} → {afterTokens:N0}"
+        var assistantText = compactResult.Changed
+            ? $"컨텍스트 압축을 수행했습니다. 입력 토큰 추정치: {beforeTokens:N0} → {afterTokens:N0}\n- 단계: {compactResult.StageSummary}\n- 절감량: {compactResult.SavedTokens:N0} tokens"
             : "현재 대화는 압축할 충분한 이전 컨텍스트가 없어 변경 없이 유지했습니다.";
 
         var assistantMsg = new ChatMessage { Role = "assistant", Content = assistantText };
@@ -6547,7 +6575,7 @@ public partial class ChatWindow : Window
         ForceScrollToEnd();
         if (StatusTokens != null)
             StatusTokens.Text = $"컨텍스트 {Services.TokenEstimator.Format(beforeTokens)} → {Services.TokenEstimator.Format(afterTokens)}";
-        SetStatus(condensed ? "컨텍스트 압축 완료" : "압축할 컨텍스트 없음", spinning: false);
+        SetStatus(compactResult.Changed ? "컨텍스트 압축 완료" : "압축할 컨텍스트 없음", spinning: false);
         RefreshContextUsageVisual();
         RefreshConversationList();
         UpdateTaskSummaryIndicators();
@@ -8081,8 +8109,7 @@ public partial class ChatWindow : Window
             // ── 전송 전 컨텍스트 사전 압축 ──
             {
                 var llm = _settings.Settings.Llm;
-                var beforeCompactTokens = Services.TokenEstimator.EstimateMessages(sendMessages);
-                var condensed = await ContextCondenser.CondenseIfNeededAsync(
+                var compactResult = await ContextCondenser.CondenseWithStatsAsync(
                     sendMessages,
                     _llm,
                     llm.MaxContextTokens,
@@ -8090,11 +8117,10 @@ public partial class ChatWindow : Window
                     llm.ContextCompactTriggerPercent,
                     false,
                     _streamCts!.Token);
-                if (condensed)
+                if (compactResult.Changed)
                 {
-                    var afterCompactTokens = Services.TokenEstimator.EstimateMessages(sendMessages);
-                    RecordCompactionStats(beforeCompactTokens, afterCompactTokens, wasAutomatic: true);
-                    SetStatus("컨텍스트를 사전 정리했습니다", spinning: true);
+                    RecordCompactionStats(compactResult, wasAutomatic: true);
+                    SetStatus($"컨텍스트를 사전 정리했습니다 · {compactResult.BeforeTokens:N0} → {compactResult.AfterTokens:N0} tokens", spinning: true);
                     RefreshContextUsageVisual();
                 }
             }
@@ -16497,7 +16523,14 @@ private static (string icon, string label, string bgHex, string fgHex) GetDecisi
             ? $"\n최근 압축: {(_lastCompactionWasAutomatic ? "자동" : "수동")} · {_lastCompactionAt.Value:HH:mm:ss}\n" +
               $"절감: {_lastCompactionBeforeTokens.Value:N0} → {_lastCompactionAfterTokens.Value:N0} tokens " +
               $"(-{Math.Max(0, _lastCompactionBeforeTokens.Value - _lastCompactionAfterTokens.Value):N0}, " +
-              $"{Services.TokenEstimator.Format(_lastCompactionBeforeTokens.Value)} → {Services.TokenEstimator.Format(_lastCompactionAfterTokens.Value)})"
+              $"{Services.TokenEstimator.Format(_lastCompactionBeforeTokens.Value)} → {Services.TokenEstimator.Format(_lastCompactionAfterTokens.Value)})\n" +
+              $"단계: {(!string.IsNullOrWhiteSpace(_lastCompactionStageSummary) ? _lastCompactionStageSummary : "기본")}"
+            : "";
+
+        var compactSession = _sessionCompactionCount > 0
+            ? $"\n세션 누적: {_sessionCompactionCount:N0}회 (자동 {_sessionAutomaticCompactionCount:N0} / 수동 {_sessionManualCompactionCount:N0})\n" +
+              $"세션 절감: {Services.TokenEstimator.Format(_sessionCompactionSavedTokens)} tokens\n" +
+              $"세션 메모리 {_sessionMemoryCompactionCount:N0}회 · 경계 {_sessionMicrocompactBoundaryCount:N0}건 · snip {_sessionSnipCompactionCount:N0}건"
             : "";
 
         TokenUsageCard.ToolTip =
@@ -16506,7 +16539,8 @@ private static (string icon, string label, string bgHex, string fgHex) GetDecisi
             $"간단 표기: {Services.TokenEstimator.Format(currentTokens)} / {Services.TokenEstimator.Format(maxContextTokens)}\n" +
             $"자동 압축 시작: {triggerPercent}%\n" +
             $"현재 입력 초안 포함" +
-            compactHistory;
+            compactHistory +
+            compactSession;
 
         UpdateCircularUsageArc(TokenUsageArc, usageRatio, 18, 18, 14);
         PositionThresholdMarker(TokenUsageThresholdMarker, triggerRatio, 18, 18, 14, 3);
@@ -16555,12 +16589,45 @@ private static (string icon, string label, string bgHex, string fgHex) GetDecisi
             centerY + radius * Math.Sin(radians));
     }
 
-    private void RecordCompactionStats(int beforeTokens, int afterTokens, bool wasAutomatic)
+    private void RecordCompactionStats(ContextCompactionResult result, bool wasAutomatic)
     {
-        _lastCompactionBeforeTokens = Math.Max(0, beforeTokens);
-        _lastCompactionAfterTokens = Math.Max(0, afterTokens);
+        var beforeTokens = Math.Max(0, result.BeforeTokens);
+        var afterTokens = Math.Max(0, result.AfterTokens);
+        var savedTokens = Math.Max(0, beforeTokens - afterTokens);
+
+        _lastCompactionBeforeTokens = beforeTokens;
+        _lastCompactionAfterTokens = afterTokens;
         _lastCompactionAt = DateTime.Now;
         _lastCompactionWasAutomatic = wasAutomatic;
+        _lastCompactionStageSummary = result.StageSummary;
+        _sessionCompactionCount++;
+        _sessionCompactionSavedTokens += savedTokens;
+        _sessionMemoryCompactionCount += result.SessionMemoryApplied ? 1 : 0;
+        _sessionMicrocompactBoundaryCount += result.MicrocompactBoundaryCount;
+        _sessionSnipCompactionCount += result.SnippedMessageCount + result.CollapsedBoundaryCount;
+        if (wasAutomatic)
+            _sessionAutomaticCompactionCount++;
+        else
+            _sessionManualCompactionCount++;
+
+        ChatConversation? conv;
+        lock (_convLock) conv = _currentConversation;
+        if (conv == null)
+            return;
+
+        conv.CompactionCount = _sessionCompactionCount;
+        conv.AutomaticCompactionCount = _sessionAutomaticCompactionCount;
+        conv.ManualCompactionCount = _sessionManualCompactionCount;
+        conv.CompactionSavedTokens = _sessionCompactionSavedTokens;
+        conv.SessionMemoryCompactionCount = _sessionMemoryCompactionCount;
+        conv.MicrocompactBoundaryCount = _sessionMicrocompactBoundaryCount;
+        conv.SnipCompactionCount = _sessionSnipCompactionCount;
+        conv.LastCompactionAt = _lastCompactionAt;
+        conv.LastCompactionWasAutomatic = wasAutomatic;
+        conv.LastCompactionBeforeTokens = beforeTokens;
+        conv.LastCompactionAfterTokens = afterTokens;
+        conv.LastCompactionStageSummary = _lastCompactionStageSummary;
+        try { _storage.Save(conv); } catch { }
     }
 
     private void ScheduleGitBranchRefresh(int delayMs = 400)