AX Agent loop 정책을 분리하고 transcript 가상화·성능 계측 구조를 강화한다

- AgentLoop 검증/문서/compact 정책 메서드를 partial 파일로 분리해 loop 본문의 책임을 줄임
- transcript 렌더에 cache pruning과 deferred scrolling을 적용해 긴 세션의 UI 부담을 낮춤
- AgentPerformanceLogService를 추가해 transcript 렌더와 agent loop 실행 요약을 perf 로그로 남김
- README와 DEVELOPMENT 문서에 2026-04-09 10:08 (KST) 기준 구조 개선 및 계측 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/Services/Agent/AgentLoopTransitions.Documents.cs

@@ -0,0 +1,156 @@
+using AxCopilot.Models;
+
+namespace AxCopilot.Services.Agent;
+
+public partial class AgentLoopService
+{
+    private void ApplyDocumentPlanSuccessTransitions(
+        LlmService.ContentBlock call,
+        ToolResult result,
+        List<ChatMessage> messages,
+        ref bool documentPlanCalled,
+        ref string? documentPlanPath,
+        ref string? documentPlanTitle,
+        ref string? documentPlanScaffold)
+    {
+        if (!string.Equals(call.ToolName, "document_plan", StringComparison.OrdinalIgnoreCase))
+            return;
+
+        documentPlanCalled = true;
+        var po = result.Output ?? string.Empty;
+        var pm = System.Text.RegularExpressions.Regex.Match(po, @"path:\s*""([^""]+)""");
+        if (pm.Success) documentPlanPath = pm.Groups[1].Value;
+        var tm = System.Text.RegularExpressions.Regex.Match(po, @"title:\s*""([^""]+)""");
+        if (tm.Success) documentPlanTitle = tm.Groups[1].Value;
+        documentPlanScaffold = ExtractDocumentPlanScaffold(po);
+
+        if (!ContainsDocumentPlanFollowUpInstruction(po))
+            return;
+
+        var toolHint = ResolveDocumentPlanFollowUpTool(po);
+        messages.Add(new ChatMessage
+        {
+            Role = "user",
+            Content =
+                "document_plan이 완료되었습니다. " +
+                "방금 생성된 골격의 [내용...] 자리와 각 섹션 내용을 실제 상세 본문으로 모두 채운 뒤 " +
+                $"{toolHint} 도구를 지금 즉시 호출하세요. " +
+                "설명만 하지 말고 실제 문서 생성 도구 호출로 바로 이어가세요."
+        });
+        EmitEvent(AgentEventType.Thinking, "", $"문서 개요 완료 · {toolHint} 실행 유도");
+    }
+
+    private static string? ExtractDocumentPlanScaffold(string output)
+    {
+        if (string.IsNullOrWhiteSpace(output))
+            return null;
+
+        var markers = new (string Start, string End)[]
+        {
+            ("--- body 시작 ---", "--- body 끝 ---"),
+            ("--- body start ---", "--- body end ---"),
+            ("<!-- body start marker -->", "<!-- body end marker -->"),
+        };
+
+        foreach (var (startMarker, endMarker) in markers)
+        {
+            var start = output.IndexOf(startMarker, StringComparison.OrdinalIgnoreCase);
+            if (start < 0)
+                continue;
+
+            var contentStart = start + startMarker.Length;
+            var end = output.IndexOf(endMarker, contentStart, StringComparison.OrdinalIgnoreCase);
+            if (end <= contentStart)
+                continue;
+
+            var scaffold = output[contentStart..end].Trim();
+            if (!string.IsNullOrWhiteSpace(scaffold))
+                return scaffold;
+        }
+
+        return null;
+    }
+
+    private static bool ContainsDocumentPlanFollowUpInstruction(string output)
+    {
+        if (string.IsNullOrWhiteSpace(output))
+            return false;
+
+        return output.Contains("즉시 실행", StringComparison.OrdinalIgnoreCase)
+               || output.Contains("immediate next step", StringComparison.OrdinalIgnoreCase)
+               || output.Contains("call html_create", StringComparison.OrdinalIgnoreCase)
+               || output.Contains("call document_assemble", StringComparison.OrdinalIgnoreCase);
+    }
+
+    private static string ResolveDocumentPlanFollowUpTool(string output)
+    {
+        if (output.Contains("document_assemble", StringComparison.OrdinalIgnoreCase))
+            return "document_assemble";
+        if (output.Contains("docx_create", StringComparison.OrdinalIgnoreCase))
+            return "docx_create";
+        if (output.Contains("markdown_create", StringComparison.OrdinalIgnoreCase))
+            return "markdown_create";
+        if (output.Contains("file_write", StringComparison.OrdinalIgnoreCase))
+            return "file_write";
+        return "html_create";
+    }
+
+    private async Task<(bool Completed, bool ConsumedExtraIteration)> TryHandleTerminalDocumentCompletionTransitionAsync(
+        LlmService.ContentBlock call,
+        ToolResult result,
+        List<LlmService.ContentBlock> toolCalls,
+        List<ChatMessage> messages,
+        Models.LlmSettings llm,
+        ModelExecutionProfileCatalog.ExecutionPolicy executionPolicy,
+        AgentContext context,
+        CancellationToken ct)
+    {
+        if (!result.Success || !IsTerminalDocumentTool(call.ToolName) || toolCalls.Count != 1)
+            return (false, false);
+
+        var verificationEnabled = executionPolicy.EnablePostToolVerification
+            && AgentTabSettingsResolver.IsPostToolVerificationEnabled(ActiveTab, llm);
+        var shouldVerify = ShouldRunPostToolVerification(
+            ActiveTab,
+            call.ToolName,
+            result.Success,
+            verificationEnabled,
+            verificationEnabled);
+        var consumedExtraIteration = false;
+        if (shouldVerify)
+        {
+            await RunPostToolVerificationAsync(messages, call.ToolName, result, context, ct);
+            consumedExtraIteration = true;
+        }
+
+        EmitEvent(AgentEventType.Complete, "", "에이전트 작업 완료");
+        return (true, consumedExtraIteration);
+    }
+
+    private async Task<bool> TryApplyPostToolVerificationTransitionAsync(
+        LlmService.ContentBlock call,
+        ToolResult result,
+        List<ChatMessage> messages,
+        Models.LlmSettings llm,
+        ModelExecutionProfileCatalog.ExecutionPolicy executionPolicy,
+        AgentContext context,
+        CancellationToken ct)
+    {
+        if (!result.Success)
+            return false;
+
+        var verificationEnabled = executionPolicy.EnablePostToolVerification
+            && AgentTabSettingsResolver.IsPostToolVerificationEnabled(ActiveTab, llm);
+        var shouldVerify = ShouldRunPostToolVerification(
+            ActiveTab,
+            call.ToolName,
+            result.Success,
+            verificationEnabled,
+            verificationEnabled);
+        if (!shouldVerify)
+            return false;
+
+        await RunPostToolVerificationAsync(messages, call.ToolName, result, context, ct);
+        return true;
+    }
+}