컨텍스트 tool_result 예산 규칙을 공용화해 query view와 압축 단계 정합성 강화

- AgentToolResultBudget helper를 추가해 오래된 tool_result를 최근 보호 구간과 aggregate budget 기준으로 공용 축약
- AgentQueryContextBuilder와 ContextCondenser가 같은 budget 규칙을 사용하도록 정리
- README와 DEVELOPMENT 문서에 2026-04-12 22:02 (KST) 기준 작업 이력 반영
- 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/Services/Agent/AgentQueryContextBuilder.cs

@@ -1,4 +1,3 @@
-using System.Text.Json;
 using AxCopilot.Models;
 
 namespace AxCopilot.Services.Agent;
@@ -18,14 +17,11 @@ public sealed class AgentQueryContextWindowResult
 }
 
 /// <summary>
-/// claude-code의 messagesForQuery 계층처럼, 저장된 전체 대화와
-/// 실제 LLM에 전송할 컨텍스트 뷰를 분리합니다.
+/// claude-code의 messagesForQuery처럼, 저장된 전체 대화와 실제 LLM에 보내는 query view를 분리합니다.
 /// </summary>
 public static class AgentQueryContextBuilder
 {
     private const int ProtectedRecentNonSystemMessages = 8;
-    private const int OldToolResultSoftCharLimit = 900;
-    private const int OldToolResultAggregateBudgetChars = 7_500;
 
     public static AgentQueryContextWindowResult Build(IReadOnlyList<ChatMessage> sourceMessages)
     {
@@ -47,7 +43,10 @@ public static class AgentQueryContextBuilder
         }
 
         var startIndex = FindWindowStartIndex(sourceMessages, out var boundaryApplied);
-        var adjustedStartIndex = AgentMessageInvariantHelper.AdjustStartIndexForToolPairs(sourceMessages, startIndex, out var preservedToolPairs);
+        var adjustedStartIndex = AgentMessageInvariantHelper.AdjustStartIndexForToolPairs(
+            sourceMessages,
+            startIndex,
+            out var preservedToolPairs);
         var toolPairExpanded = adjustedStartIndex < startIndex;
 
         var windowMessages = new List<ChatMessage>(sourceMessages.Count);
@@ -62,7 +61,7 @@ public static class AgentQueryContextBuilder
         }
 
         var tokensBeforeBudget = TokenEstimator.EstimateMessages(windowMessages);
-        var truncatedToolResults = ApplyOldToolResultBudget(windowMessages);
+        var budgetResult = AgentToolResultBudget.Apply(windowMessages, ProtectedRecentNonSystemMessages);
         var tokensAfterBudget = TokenEstimator.EstimateMessages(windowMessages);
 
         return new AgentQueryContextWindowResult
@@ -74,7 +73,7 @@ public static class AgentQueryContextBuilder
             BoundaryApplied = boundaryApplied,
             ToolPairExpanded = toolPairExpanded,
             PreservedToolPairCount = preservedToolPairs,
-            TruncatedToolResultCount = truncatedToolResults,
+            TruncatedToolResultCount = budgetResult.TruncatedCount,
             TokensBeforeBudget = tokensBeforeBudget,
             TokensAfterBudget = tokensAfterBudget,
         };
@@ -112,88 +111,6 @@ public static class AgentQueryContextBuilder
                || content.StartsWith("[이전 압축 경계 병합", StringComparison.Ordinal);
     }
 
-    private static int ApplyOldToolResultBudget(List<ChatMessage> messages)
-    {
-        var nonSystemIndexes = messages
-            .Select((message, index) => new { message, index })
-            .Where(x => !string.Equals(x.message.Role, "system", StringComparison.OrdinalIgnoreCase))
-            .Select(x => x.index)
-            .ToList();
-
-        if (nonSystemIndexes.Count <= ProtectedRecentNonSystemMessages)
-            return 0;
-
-        var protectedStart = nonSystemIndexes[Math.Max(0, nonSystemIndexes.Count - ProtectedRecentNonSystemMessages)];
-        var spentChars = 0;
-        var truncatedCount = 0;
-
-        for (var i = 0; i < protectedStart; i++)
-        {
-            var message = messages[i];
-            if (!AgentMessageInvariantHelper.TryGetToolResultId(message, out _))
-                continue;
-
-            var content = message.Content ?? "";
-            if (string.IsNullOrWhiteSpace(content))
-                continue;
-
-            spentChars += content.Length;
-            if (content.Length <= OldToolResultSoftCharLimit && spentChars <= OldToolResultAggregateBudgetChars)
-                continue;
-
-            var truncated = TruncateToolResultJson(content);
-            if (string.Equals(truncated, content, StringComparison.Ordinal))
-                continue;
-
-            messages[i] = CloneMessage(message, truncated);
-            truncatedCount++;
-        }
-
-        return truncatedCount;
-    }
-
-    private static string TruncateToolResultJson(string json)
-    {
-        try
-        {
-            using var doc = JsonDocument.Parse(json);
-            var root = doc.RootElement;
-            var toolType = root.TryGetProperty("type", out var typeEl) ? typeEl.GetString() ?? "" : "";
-            if (!string.Equals(toolType, "tool_result", StringComparison.Ordinal))
-                return json;
-
-            var toolUseId = root.TryGetProperty("tool_use_id", out var idEl) ? idEl.GetString() ?? "" : "";
-            var toolName = root.TryGetProperty("tool_name", out var nameEl) ? nameEl.GetString() ?? "" : "";
-            var content = root.TryGetProperty("content", out var contentEl) ? contentEl.GetString() ?? "" : "";
-            if (content.Length <= OldToolResultSoftCharLimit)
-                return json;
-
-            var keepHead = Math.Min(360, content.Length);
-            var keepTail = Math.Min(220, Math.Max(0, content.Length - keepHead));
-            var head = content[..keepHead];
-            var tail = keepTail > 0 ? content[^keepTail..] : "";
-            var compacted = head +
-                            $"\n...[query-view tool_result 축약: {content.Length:N0}자]...\n" +
-                            tail;
-
-            return JsonSerializer.Serialize(new
-            {
-                type = "tool_result",
-                tool_use_id = toolUseId,
-                tool_name = toolName,
-                content = compacted
-            });
-        }
-        catch
-        {
-            if (json.Length <= OldToolResultSoftCharLimit)
-                return json;
-
-            var head = json[..Math.Min(OldToolResultSoftCharLimit, json.Length)];
-            return head + "...[query-view 축약됨]";
-        }
-    }
-
     private static ChatMessage CloneMessage(ChatMessage source, string? contentOverride = null)
     {
         return new ChatMessage