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)

AGENTS.md

@@ -203,6 +203,12 @@ if (!enabled) return ToolResult.Ok("비활성 상태입니다. 설정에서 활
 - 모든 변경 후 `dotnet build` 실행 → **경고 0, 오류 0** 필수
 - CS8603 (nullable) 경고 즉시 수정
 
+### 성능/실행속도 우선 원칙
+- 기능 구현 시 가능하면 **개발 단계부터 최적화와 실행 속도**를 함께 고려합니다.
+- 동일 품질을 만족하는 구현안이 여러 개라면, **더 가볍고 빠르게 동작하는 구조**를 우선 채택합니다.
+- UI/UX 개선, 에이전트 루프, 도구 실행, 컨텍스트 압축, 검색/필터링 기능은 특히 초기 구현부터 불필요한 반복 계산·과도한 렌더링·중복 I/O를 줄이는 방향으로 설계합니다.
+- 단, 성능 최적화를 이유로 가독성이나 안정성을 과도하게 해치지 않으며, **동등 품질 + 유지보수 가능성**을 함께 만족하는 수준에서 최적화합니다.
+
 ### 리소스 관리
 - `IDisposable` 구현 객체는 반드시 해제 (PerformanceCounter, LspClientService 등)
 - P/Invoke 메모리: `Marshal.AllocHGlobal` 후 `finally`에서 `FreeHGlobal`

README.md

@@ -8,6 +8,11 @@ Windows 전용 시맨틱 런처 & 워크스페이스 매니저
 `docs/claw-code-parity-plan.md`
 
 
+- 업데이트: 2026-04-04 23:47 (KST)
+- AX Agent 컨텍스트 압축 경로에 `session memory compact`, `microcompact`, `collapse/snip` 단계를 추가해 오래된 요약·실행 로그·도구 결과를 LLM 요약 전에 더 세밀하게 줄이도록 보강했습니다.
+- 현재 대화 기준 compact 누적 회수, 자동/수동 비중, 절감 토큰, session memory 적용 횟수, microcompact/snipped 메시지 수를 하단 컨텍스트 카드 hover에서 함께 확인할 수 있게 했습니다.
+- 검증: `dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\\verify\\ -p:IntermediateOutputPath=obj\\verify\\` 경고 0 / 오류 0
+
 
 - 업데이트: 2026-04-04 23:32 (KST)
 - AX Agent 컨텍스트 압축 경로에 `microcompact` 성격의 선행 경량 압축 단계를 추가해, 오래된 실행 로그·도구 결과·긴 메시지를 먼저 경계 요약으로 줄인 뒤 LLM 요약 단계로 넘기도록 보강했습니다.

docs/DEVELOPMENT.md

@@ -1,4 +1,7 @@
-# AX Copilot - ?? ??
+# AX Copilot - 개발 문서
+
+- Document update: 2026-04-04 23:47 (KST) - Added AX-side session-memory compaction, collapse/snip trimming, and per-conversation compaction usage tracking so compact now records staged reductions instead of only the last before/after snapshot.
+- Document update: 2026-04-04 23:47 (KST) - The AX Agent context tooltip now shows session totals for compaction count, saved tokens, session-memory passes, microcompact boundaries, and snipped messages for the current conversation.
 
 - Document update: 2026-04-04 23:32 (KST) - Upgraded ContextCondenser from a two-step path to a three-step path (tool-result truncate -> microcompact -> summarize) so long sessions can strip older execution/tool chatter before invoking the LLM summary stage.
 - Document update: 2026-04-04 23:32 (KST) - Added AX-side microcompact boundaries that compress older tool results, execution metadata, and oversized messages into lighter boundary summaries, bringing the compact flow closer to the staged approach used in claude-code.
@@ -4084,4 +4087,4 @@ ow + toggle 시각 언어로 다시 정렬했다.
 - AX Agent 하단 컨텍스트 카드의 툴팁에 최근 compact 이력을 추가해 마지막 자동/수동 압축 시각, 압축 전후 토큰 수, 절감량을 이후에도 다시 확인할 수 있게 보강했다.
 - 수동 `/compact`와 전송 전 자동 컨텍스트 압축이 모두 같은 `RecordCompactionStats(...)` 경로를 사용하도록 맞춰, 압축 결과가 일회성 상태 메시지에만 머물지 않고 UI에서 재참조 가능하도록 정리했다.
 - 이번 라운드부터 `claude-code`의 compact 소스를 기준으로 `session memory compaction → microcompact → context collapse/snip → autocompact → post-compaction 계측` 흐름을 AX 기준과 비교 분석할 준비를 진행했다.
-- 검증: dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\verify\ -p:IntermediateOutputPath=obj\verify\ (경고 0 / 오류 0)
+- 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/Models/ChatModels.cs

@@ -139,6 +139,42 @@ public class ChatConversation
 
     [JsonPropertyName("conversationSortMode")]
     public string ConversationSortMode { get; set; } = "activity";
+
+    [JsonPropertyName("compactionCount")]
+    public int CompactionCount { get; set; }
+
+    [JsonPropertyName("automaticCompactionCount")]
+    public int AutomaticCompactionCount { get; set; }
+
+    [JsonPropertyName("manualCompactionCount")]
+    public int ManualCompactionCount { get; set; }
+
+    [JsonPropertyName("compactionSavedTokens")]
+    public int CompactionSavedTokens { get; set; }
+
+    [JsonPropertyName("sessionMemoryCompactionCount")]
+    public int SessionMemoryCompactionCount { get; set; }
+
+    [JsonPropertyName("microcompactBoundaryCount")]
+    public int MicrocompactBoundaryCount { get; set; }
+
+    [JsonPropertyName("snipCompactionCount")]
+    public int SnipCompactionCount { get; set; }
+
+    [JsonPropertyName("lastCompactionAt")]
+    public DateTime? LastCompactionAt { get; set; }
+
+    [JsonPropertyName("lastCompactionWasAutomatic")]
+    public bool LastCompactionWasAutomatic { get; set; }
+
+    [JsonPropertyName("lastCompactionBeforeTokens")]
+    public int? LastCompactionBeforeTokens { get; set; }
+
+    [JsonPropertyName("lastCompactionAfterTokens")]
+    public int? LastCompactionAfterTokens { get; set; }
+
+    [JsonPropertyName("lastCompactionStageSummary")]
+    public string? LastCompactionStageSummary { get; set; }
 }
 
 public class ChatAgentRunRecord

src/AxCopilot/Services/Agent/ContextCondenser.cs

@@ -2,14 +2,32 @@
 
 namespace AxCopilot.Services.Agent;
 
+public sealed class ContextCompactionResult
+{
+    public bool Changed { get; set; }
+    public int BeforeTokens { get; set; }
+    public int AfterTokens { get; set; }
+    public bool SessionMemoryApplied { get; set; }
+    public int SessionMemoryMergedMessages { get; set; }
+    public int MicrocompactBoundaryCount { get; set; }
+    public int MicrocompactSingleCount { get; set; }
+    public int SnippedMessageCount { get; set; }
+    public int CollapsedBoundaryCount { get; set; }
+    public List<string> AppliedStages { get; } = new();
+    public int SavedTokens => Math.Max(0, BeforeTokens - AfterTokens);
+    public string StageSummary => AppliedStages.Count == 0 ? "없음" : string.Join(" -> ", AppliedStages);
+}
+
 /// <summary>
 /// 컨텍스트 윈도우 관리: 대화가 길어지면 이전 메시지를 요약하여 압축합니다.
 /// MemGPT/OpenHands의 LLMSummarizingCondenser 패턴을 경량 구현.
 ///
-/// 3단계 압축 전략:
+/// 5단계 압축 전략:
 ///  1단계 — 도구 결과 자르기: 대용량 tool_result 출력을 핵심만 남기고 축약 (LLM 호출 없음)
-///  2단계 — microcompact: 오래된 실행 로그/도구 묶음을 경계 요약으로 치환 (LLM 호출 없음)
-///  3단계 — 이전 대화 요약: 오래된 메시지를 LLM으로 요약하여 교체 (LLM 1회 호출)
+///  2단계 — session memory compact: 이전 경계/요약을 하나의 세션 메모로 통합
+///  3단계 — microcompact: 오래된 실행 로그/도구 묶음을 경계 요약으로 치환 (LLM 호출 없음)
+///  4단계 — collapse/snip: 긴 로그/도구 결과를 더 짧은 경계/앞뒤 일부로 절단
+///  5단계 — 이전 대화 요약: 오래된 메시지를 LLM으로 요약하여 교체 (LLM 1회 호출)
 /// </summary>
 public static class ContextCondenser
 {
@@ -17,6 +35,8 @@ public static class ContextCondenser
     private const int MaxToolResultChars = 1500;
     private const int MicrocompactSingleKeepChars = 480;
     private const int MicrocompactGroupMinCount = 2;
+    private const int SnipKeepHeadChars = 220;
+    private const int SnipKeepTailChars = 140;
 
     /// <summary>요약 시 유지할 최근 메시지 수</summary>
     private const int RecentKeepCount = 6;
@@ -51,8 +71,22 @@ public static class ContextCondenser
         bool force = false,
         CancellationToken ct = default)
     {
-        if (messages.Count < 6) return false;
-        if (!force && !proactiveEnabled) return false;
+        var result = await CondenseWithStatsAsync(messages, llm, maxOutputTokens, proactiveEnabled, triggerPercent, force, ct);
+        return result.Changed;
+    }
+
+    public static async Task<ContextCompactionResult> CondenseWithStatsAsync(
+        List<ChatMessage> messages,
+        LlmService llm,
+        int maxOutputTokens,
+        bool proactiveEnabled = true,
+        int triggerPercent = 80,
+        bool force = false,
+        CancellationToken ct = default)
+    {
+        var result = new ContextCompactionResult();
+        if (messages.Count < 6) return result;
+        if (!force && !proactiveEnabled) return result;
 
         // 현재 모델의 입력 토큰 한도
         var settings = llm.GetCurrentModelInfo();
@@ -62,34 +96,106 @@ public static class ContextCondenser
         var threshold = (int)(effectiveMax * (percent / 100.0)); // 설정 임계치에서 압축 시작
 
         var currentTokens = TokenEstimator.EstimateMessages(messages);
-        if (!force && currentTokens < threshold) return false;
+        result.BeforeTokens = currentTokens;
+        if (!force && currentTokens < threshold)
+        {
+            result.AfterTokens = currentTokens;
+            return result;
+        }
         var originalTokens = currentTokens;
 
         bool didCompress = false;
 
         // ── 1단계: 도구 결과 축약 (LLM 호출 없음, 즉시 실행) ──
-        didCompress |= TruncateToolResults(messages);
+        if (TruncateToolResults(messages))
+        {
+            didCompress = true;
+            result.AppliedStages.Add("tool-result");
+        }
 
         // 1단계 후 다시 추정
         currentTokens = TokenEstimator.EstimateMessages(messages);
-        if (!force && currentTokens < threshold) return didCompress;
+        if (!force && currentTokens < threshold)
+        {
+            result.Changed = didCompress;
+            result.AfterTokens = currentTokens;
+            return result;
+        }
 
-        // ── 2단계: 오래된 실행/도구 묶음 경량 압축 ──
-        didCompress |= MicrocompactOlderMessages(messages);
+        // ── 2단계: 이전 경계/요약을 세션 메모로 통합 ──
+        var sessionMemoryMergedMessages = SessionMemoryCompactOlderMessages(messages);
+        if (sessionMemoryMergedMessages > 0)
+        {
+            didCompress = true;
+            result.SessionMemoryApplied = true;
+            result.SessionMemoryMergedMessages = sessionMemoryMergedMessages;
+            result.AppliedStages.Add("session-memory");
+        }
 
         currentTokens = TokenEstimator.EstimateMessages(messages);
-        if (!force && currentTokens < threshold) return didCompress;
+        if (!force && currentTokens < threshold)
+        {
+            result.Changed = didCompress;
+            result.AfterTokens = currentTokens;
+            return result;
+        }
 
-        // ── 3단계: 이전 대화 LLM 요약 ──
-        didCompress |= await SummarizeOldMessagesAsync(messages, llm, ct);
+        // ── 3단계: 오래된 실행/도구 묶음 경량 압축 ──
+        var (boundaryCount, singleCount) = MicrocompactOlderMessages(messages);
+        if (boundaryCount > 0 || singleCount > 0)
+        {
+            didCompress = true;
+            result.MicrocompactBoundaryCount = boundaryCount;
+            result.MicrocompactSingleCount = singleCount;
+            result.AppliedStages.Add("microcompact");
+        }
+
+        currentTokens = TokenEstimator.EstimateMessages(messages);
+        if (!force && currentTokens < threshold)
+        {
+            result.Changed = didCompress;
+            result.AfterTokens = currentTokens;
+            return result;
+        }
+
+        // ── 4단계: collapse/snip ──
+        var (snippedCount, collapsedCount) = CollapseAndSnipOlderMessages(messages);
+        if (snippedCount > 0 || collapsedCount > 0)
+        {
+            didCompress = true;
+            result.SnippedMessageCount = snippedCount;
+            result.CollapsedBoundaryCount = collapsedCount;
+            result.AppliedStages.Add("snip");
+        }
+
+        currentTokens = TokenEstimator.EstimateMessages(messages);
+        if (!force && currentTokens < threshold)
+        {
+            result.Changed = didCompress;
+            result.AfterTokens = currentTokens;
+            return result;
+        }
+
+        // ── 5단계: 이전 대화 LLM 요약 ──
+        if (await SummarizeOldMessagesAsync(messages, llm, ct))
+        {
+            didCompress = true;
+            result.AppliedStages.Add("summary");
+        }
 
         if (didCompress)
         {
             var afterTokens = TokenEstimator.EstimateMessages(messages);
             LogService.Info($"Context Condenser: {originalTokens} → {afterTokens} 토큰 (절감 {originalTokens - afterTokens})");
+            result.Changed = true;
+            result.AfterTokens = afterTokens;
+        }
+        else
+        {
+            result.AfterTokens = currentTokens;
         }
 
-        return didCompress;
+        return result;
     }
 
     /// <summary>
@@ -164,11 +270,11 @@ public static class ContextCondenser
     /// 오래된 실행 로그/도구 결과/비정상적으로 긴 메시지를 먼저 경량 경계 요약으로 묶습니다.
     /// claw-code의 microcompact처럼 LLM 호출 전에 토큰을 한 번 더 줄이는 단계입니다.
     /// </summary>
-    private static bool MicrocompactOlderMessages(List<ChatMessage> messages)
+    private static (int BoundaryCount, int SingleCount) MicrocompactOlderMessages(List<ChatMessage> messages)
     {
         var systemMsg = messages.FirstOrDefault(m => m.Role == "system");
         var nonSystemMessages = messages.Where(m => m.Role != "system").ToList();
-        if (nonSystemMessages.Count <= RecentKeepCount + 2) return false;
+        if (nonSystemMessages.Count <= RecentKeepCount + 2) return (0, 0);
 
         var keepCount = Math.Min(RecentKeepCount, nonSystemMessages.Count);
         var recentMessages = nonSystemMessages.Skip(nonSystemMessages.Count - keepCount).ToList();
@@ -176,6 +282,8 @@ public static class ContextCondenser
 
         var rewritten = new List<ChatMessage>(oldMessages.Count);
         bool changed = false;
+        int boundaryCount = 0;
+        int singleCount = 0;
 
         for (int i = 0; i < oldMessages.Count;)
         {
@@ -194,12 +302,14 @@ public static class ContextCondenser
                 {
                     rewritten.Add(BuildMicrocompactBoundary(group));
                     changed = true;
+                    boundaryCount++;
                 }
                 else
                 {
                     var singleChanged = TryMicrocompactSingle(group[0], out var compacted);
                     rewritten.Add(singleChanged ? compacted : group[0]);
                     changed |= singleChanged;
+                    if (singleChanged) singleCount++;
                 }
 
                 i = j;
@@ -210,6 +320,7 @@ public static class ContextCondenser
             {
                 rewritten.Add(singleCompacted);
                 changed = true;
+                singleCount++;
             }
             else
             {
@@ -219,12 +330,204 @@ public static class ContextCondenser
             i++;
         }
 
-        if (!changed) return false;
+        if (!changed) return (0, 0);
 
         messages.Clear();
         if (systemMsg != null) messages.Add(systemMsg);
         messages.AddRange(rewritten);
         messages.AddRange(recentMessages);
+        return (boundaryCount, singleCount);
+    }
+
+    private static int SessionMemoryCompactOlderMessages(List<ChatMessage> messages)
+    {
+        var systemMsg = messages.FirstOrDefault(m => m.Role == "system");
+        var nonSystemMessages = messages.Where(m => m.Role != "system").ToList();
+        if (nonSystemMessages.Count <= RecentKeepCount + 3) return 0;
+
+        var keepCount = Math.Min(RecentKeepCount, nonSystemMessages.Count);
+        var recentMessages = nonSystemMessages.Skip(nonSystemMessages.Count - keepCount).ToList();
+        var oldMessages = nonSystemMessages.Take(nonSystemMessages.Count - keepCount).ToList();
+
+        var candidates = oldMessages
+            .Select((message, index) => new { message, index })
+            .Where(x => IsSessionMemoryCandidate(x.message))
+            .ToList();
+
+        if (candidates.Count < 2) return 0;
+
+        var attachedFiles = candidates
+            .SelectMany(x => x.message.AttachedFiles ?? Enumerable.Empty<string>())
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .Select(path =>
+            {
+                try { return System.IO.Path.GetFileName(path); }
+                catch { return path; }
+            })
+            .Where(name => !string.IsNullOrWhiteSpace(name))
+            .Take(5)
+            .ToList();
+
+        var merged = new ChatMessage
+        {
+            Role = "assistant",
+            Timestamp = candidates.Last().message.Timestamp,
+            MetaKind = "session_memory_compaction",
+            MetaRunId = candidates.Last().message.MetaRunId,
+            AttachedFiles = attachedFiles.Count > 0 ? attachedFiles : null,
+            Content = string.Join("\n", new[]
+            {
+                $"[세션 메모리 압축 - {candidates.Count}개 이전 경계 통합]",
+                "- 이전 요약, 실행 경계, 오래된 메타 로그를 하나의 세션 메모로 합쳤습니다.",
+                attachedFiles.Count > 0 ? $"- 관련 파일: {string.Join(", ", attachedFiles)}" : "- 관련 파일: 없음",
+            })
+        };
+
+        var rewritten = new List<ChatMessage>(oldMessages.Count - candidates.Count + 1);
+        bool inserted = false;
+        for (int i = 0; i < oldMessages.Count; i++)
+        {
+            if (candidates.Any(x => x.index == i))
+            {
+                if (!inserted)
+                {
+                    rewritten.Add(merged);
+                    inserted = true;
+                }
+                continue;
+            }
+
+            rewritten.Add(oldMessages[i]);
+        }
+
+        messages.Clear();
+        if (systemMsg != null) messages.Add(systemMsg);
+        messages.AddRange(rewritten);
+        messages.AddRange(recentMessages);
+        return candidates.Count;
+    }
+
+    private static bool IsSessionMemoryCandidate(ChatMessage message)
+    {
+        var content = message.Content ?? "";
+        if (string.IsNullOrWhiteSpace(content)) return false;
+
+        return string.Equals(message.MetaKind, "microcompact_boundary", StringComparison.OrdinalIgnoreCase)
+               || string.Equals(message.MetaKind, "session_memory_compaction", StringComparison.OrdinalIgnoreCase)
+               || content.StartsWith("[이전 대화 요약", StringComparison.Ordinal)
+               || content.StartsWith("[이전 실행 묶음 압축", StringComparison.Ordinal)
+               || content.StartsWith("[이전 도구 결과 축약", StringComparison.Ordinal)
+               || content.StartsWith("[이전 도구 호출 묶음 축약", StringComparison.Ordinal)
+               || content.StartsWith("[이전 실행 메타 축약", StringComparison.Ordinal);
+    }
+
+    private static (int SnippedCount, int CollapsedCount) CollapseAndSnipOlderMessages(List<ChatMessage> messages)
+    {
+        var systemMsg = messages.FirstOrDefault(m => m.Role == "system");
+        var nonSystemMessages = messages.Where(m => m.Role != "system").ToList();
+        if (nonSystemMessages.Count <= RecentKeepCount + 2) return (0, 0);
+
+        var keepCount = Math.Min(RecentKeepCount, nonSystemMessages.Count);
+        var recentMessages = nonSystemMessages.Skip(nonSystemMessages.Count - keepCount).ToList();
+        var oldMessages = nonSystemMessages.Take(nonSystemMessages.Count - keepCount).ToList();
+
+        var rewritten = new List<ChatMessage>(oldMessages.Count);
+        int snippedCount = 0;
+        int collapsedCount = 0;
+
+        for (int i = 0; i < oldMessages.Count;)
+        {
+            var current = oldMessages[i];
+            if (IsBoundaryLike(current))
+            {
+                var group = new List<ChatMessage> { current };
+                int j = i + 1;
+                while (j < oldMessages.Count && IsBoundaryLike(oldMessages[j]))
+                {
+                    group.Add(oldMessages[j]);
+                    j++;
+                }
+
+                if (group.Count >= 2)
+                {
+                    rewritten.Add(new ChatMessage
+                    {
+                        Role = "assistant",
+                        Timestamp = group.Last().Timestamp,
+                        MetaKind = "collapsed_boundary",
+                        MetaRunId = group.Last().MetaRunId,
+                        Content = $"[이전 압축 경계 병합 - {group.Count}개]\n- 이전 compact/snippet 경계를 하나로 합쳤습니다."
+                    });
+                    collapsedCount += group.Count;
+                    i = j;
+                    continue;
+                }
+            }
+
+            if (TrySnipMessage(current, out var snipped))
+            {
+                rewritten.Add(snipped);
+                snippedCount++;
+            }
+            else
+            {
+                rewritten.Add(current);
+            }
+
+            i++;
+        }
+
+        if (snippedCount == 0 && collapsedCount == 0) return (0, 0);
+
+        messages.Clear();
+        if (systemMsg != null) messages.Add(systemMsg);
+        messages.AddRange(rewritten);
+        messages.AddRange(recentMessages);
+        return (snippedCount, collapsedCount);
+    }
+
+    private static bool IsBoundaryLike(ChatMessage message)
+    {
+        var content = message.Content ?? "";
+        return string.Equals(message.MetaKind, "microcompact_boundary", StringComparison.OrdinalIgnoreCase)
+               || string.Equals(message.MetaKind, "session_memory_compaction", StringComparison.OrdinalIgnoreCase)
+               || content.StartsWith("[이전 실행 묶음 압축", StringComparison.Ordinal)
+               || content.StartsWith("[세션 메모리 압축", StringComparison.Ordinal)
+               || content.StartsWith("[이전 압축 경계 병합", StringComparison.Ordinal);
+    }
+
+    private static bool TrySnipMessage(ChatMessage source, out ChatMessage snipped)
+    {
+        snipped = source;
+        var content = source.Content ?? "";
+        if (string.IsNullOrWhiteSpace(content)) return false;
+        if (source.Role == "system") return false;
+        if (content.Length < 900 && content.Split('\n').Length < 12) return false;
+
+        var normalized = content.Replace("\r\n", "\n");
+        var lines = normalized
+            .Split('\n')
+            .Select(line => line.TrimEnd())
+            .Where(line => !string.IsNullOrWhiteSpace(line))
+            .ToList();
+
+        if (lines.Count >= 6)
+        {
+            var headLines = lines.Take(3);
+            var tailLines = lines.TakeLast(2);
+            snipped = CloneWithContent(
+                source,
+                string.Join("\n", headLines) +
+                "\n...[snip: 중간 실행 로그/출력 축약]...\n" +
+                string.Join("\n", tailLines));
+            return true;
+        }
+
+        var head = normalized[..Math.Min(SnipKeepHeadChars, normalized.Length)];
+        var tail = normalized.Length > SnipKeepTailChars ? normalized[^SnipKeepTailChars..] : "";
+        snipped = CloneWithContent(
+            source,
+            head + "\n...[snip: 중간 내용 축약]...\n" + tail);
         return true;
     }
 

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)