diff --git a/CLAUDE.md b/CLAUDE.md
index 4d1c885..6b19f08 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -7,6 +7,59 @@
 
 ## 완료된 작업
 
+### 문서 탐색기 (Tab 16) 구현 (2026-05-24)
+
+#### 배경
+프로젝트 폴더의 문서를 Web UI에서 직접 보고 관리. 트리는 **프로젝트 폴더 전체**를 탐색,
+뷰어는 **txt · md · pdf** 3종(그 외 다운로드), **보기 + 관리 + 인라인 편집** 범위.
+사용자 결정: PDF=원본 그대로(iframe), Excel=제외, md 렌더=marked+코드강조+KaTeX+mermaid,
+뷰어 바탕=흰색.
+
+#### 구현 내역
+
+| # | 항목 | 핵심 |
+|---|------|------|
+| 1 | 안전 파일트리 | 루트 자동탐색(.git/*.sln) → 상대경로만 취급, `Path.GetFullPath` 정규화 후 루트이탈·심볼릭이탈 차단. 제외 디렉토리(.git/bin/obj/node_modules/storage…)·민감파일(*.pfx/.env/appsettings*.json…) 숨김+차단 |
+| 2 | 뷰어 디스패치 | `md`=marked→DOMPurify→hljs→KaTeX→mermaid / `pdf`=원본 iframe(`Content-Type: application/pdf`) / `txt`=pre / 그 외=다운로드. md 라이브러리는 첫 진입 시 지연로딩 |
+| 3 | 인라인 편집 | admin이면 `✎ 편집` → textarea(md는 실시간 분할 미리보기) → `PUT /api/docs/text` 저장 |
+| 4 | 관리 | 새 폴더·업로드·이름변경·재귀삭제 — KB admin 토큰(X-Kb-Token) 재사용 |
+| 5 | UI | 다크 트리(지연확장·필터·노드별 hover 액션) + **흰색 종이 뷰어**, 상대링크 클릭 시 탐색기 내 이동, 토스트 |
+
+#### 수정 파일
+
+| 파일 | 변경 요약 |
+|------|----------|
+| `src/Infrastructure/Docs/DocBrowserService.cs` (신규) | 루트결정·`SafeResolve`(이탈/심볼릭/제외/민감 가드)·List/ReadText(바이너리·BOM·크기상한)/OpenRaw(MIME)/WriteText/Rename/Delete/MakeDir/SaveUploadAsync |
+| `src/Web/Controllers/DocsController.cs` (신규) | `/api/docs` — config·tree·text·raw(공개) / PUT text·rename·mkdir·upload·DELETE(admin, `IKbAuthService.ValidateAsync`) |
+| `src/Web/Program.cs` | `DocBrowserService` 싱글톤 등록 |
+| `src/Web/appsettings.json` | `DocBrowser` 섹션(Root="", MaxTextBytes=2MB, MaxUploadBytes=50MB) |
+| `src/Web/wwwroot/index.html` | nav-item(16 문서 탐색기), `#pane-docs`(트리+뷰어), docs.css 링크, docs.js 스크립트 |
+| `src/Web/wwwroot/js/app.js` | 탭 전환부 `if (tab === 'docs') docsInit()` |
+| `src/Web/wwwroot/js/docs.js` (신규) | 트리(지연확장·필터·관리액션 위임), 뷰어 디스패치, md 렌더 파이프라인, 지연 라이브러리 로더, 인라인 에디터, 관리(mkdir/upload/rename/delete), KB 토큰 재사용 잠금해제, 토스트 |
+| `src/Web/wwwroot/css/docs.css` (신규) | 다크 트리 + 흰색 종이 뷰어, GitHub-라이트 마크다운 타이포, 편집 분할 |
+| `src/Web/wwwroot/lib/` (신규) | marked@12, dompurify@3.1.6, highlight.js@11.10(+github 테마), katex@0.16.11(js/css/auto-render + woff2 20종), mermaid@10.9.1 — 전부 로컬 번들 |
+
+#### 설계 결정
+
+| 항목 | 결정 |
+|------|------|
+| 적용 환경 | **소스 트리가 있는 개발 환경 전용** (배포본 `/opt/ExperionCrawler`엔 소스 없음). 루트는 `DocBrowser:Root`로 재설정 가능 |
+| 인증 | 조회=공개, 변경계열=KB admin 토큰 재사용(별도 비번 없음). 프론트는 `sessionStorage.kbToken` 공유 |
+| md 라이브러리 로딩 | 페이지 로드 시점이 아닌 **md 첫 열람 시 지연로딩**(mermaid 3.3MB 등 무게 회피) |
+| XSS | marked 출력은 DOMPurify 살균. pdf/원본은 iframe·MIME 한정 |
+| download 파라미터 | ASP.NET bool 바인딩은 `true/false`만 허용 — 프론트 `download=true` 사용(초기 `download=1`은 400, 수정함) |
+| 뷰어 대상 | 우선 txt/md/pdf만. `DOCS_TEXT_EXT`/`DOCS_MD_EXT` 상수로 추후 확장 용이 |
+
+#### 빌드/검증 (라이브 :5000)
+- `dotnet build` 경고 0 / 에러 0, `node -c docs.js/app.js` OK, 정적자산 11종 200 서빙
+- 루트 자동탐색 → 프로젝트 루트, 트리 `.git/bin/obj` 제외, 경로이탈·민감파일(appsettings/.env)·`.git` 진입 차단
+- md/txt 읽기·하위트리·PDF inline(`application/pdf`)·다운로드 첨부 정상
+- 미인증 PUT/DELETE → 401, admin 로그인 후 mkdir/쓰기/읽기/이름변경/재귀삭제 정상, `.env` 쓰기 차단, 정리 확인
+
+#### 잔여
+- 브라우저 실물 렌더(트리 클릭·md/mermaid/KaTeX·편집 UI)는 미확인 — 사용자 `Ctrl+F5` 후 탭 진입으로 확인 필요
+- 검증 위해 기존 `dotnet run`(터미널)을 백그라운드 새 빌드로 교체 기동
+
 ### Phase 7 + Phase 5 후순위 일괄 구현 (2026-05-14)
 
 #### 배경
diff --git a/src/Infrastructure/Docs/DocBrowserService.cs b/src/Infrastructure/Docs/DocBrowserService.cs
new file mode 100644
index 0000000..fa23eee
--- /dev/null
+++ b/src/Infrastructure/Docs/DocBrowserService.cs
@@ -0,0 +1,350 @@
+using System.Text;
+using System.Text.RegularExpressions;
+using Microsoft.Extensions.Configuration;
+
+namespace ExperionCrawler.Infrastructure.Docs;
+
+/// <summary>디렉토리/파일 한 항목.</summary>
+public sealed record DocEntry(string Name, string RelPath, bool IsDir, long Size, DateTime ModifiedUtc, string Ext);
+
+/// <summary>텍스트 읽기 결과.</summary>
+public sealed record DocTextResult(string Text, bool Truncated, long Size, string Ext);
+
+/// <summary>원본 스트림 + 메타.</summary>
+public sealed record DocRawResult(Stream Stream, string ContentType, string FileName, string Ext);
+
+/// <summary>경로 이탈·제외·미존재 등 안전 위반.</summary>
+public sealed class DocBrowserException : Exception
+{
+    public DocBrowserException(string message) : base(message) { }
+}
+
+/// <summary>
+/// 프로젝트 폴더 트리를 안전하게 탐색/편집하기 위한 서비스.
+/// 모든 경로는 루트 기준 상대경로로만 다루며, 루트 이탈·제외 디렉토리·민감 파일은 차단한다.
+/// 루트는 DocBrowser:Root 설정 또는 (.git/*.sln 자동탐색)으로 결정. 소스 트리가 있는 개발 환경 전용.
+/// </summary>
+public sealed class DocBrowserService
+{
+    private readonly string _root;
+    private readonly long _maxTextBytes;
+    private readonly long _maxUploadBytes;
+
+    // 트리에서 통째로 감출 디렉토리 이름 (대소문자 무시)
+    private static readonly HashSet<string> ExcludedDirs = new(StringComparer.OrdinalIgnoreCase)
+    {
+        ".git", ".hg", ".svn", "bin", "obj", "node_modules", ".vs", ".vscode", ".idea",
+        ".venv", "venv", "env", "__pycache__", ".pytest_cache", ".mypy_cache",
+        "dist", "build", "packages", "TestResults", "storage", "data", ".claude",
+    };
+
+    // 숨기고 읽기/서빙/편집 모두 차단할 민감 파일 패턴
+    private static readonly string[] SensitiveGlobs =
+    {
+        "*.pfx", "*.p12", "*.pem", "*.key", "*.crt", "*.cer",
+        ".env", ".env.*", "appsettings*.json", "secrets.json", "*.user", "*.suo",
+        "id_rsa", "id_rsa.*", "*.pyc",
+    };
+
+    public DocBrowserService(IConfiguration config)
+    {
+        _root = ResolveRoot(config["DocBrowser:Root"]);
+        _maxTextBytes = ParseLong(config["DocBrowser:MaxTextBytes"], 2L * 1024 * 1024);   // 2 MB
+        _maxUploadBytes = ParseLong(config["DocBrowser:MaxUploadBytes"], 50L * 1024 * 1024); // 50 MB
+    }
+
+    public string Root => _root;
+    public long MaxTextBytes => _maxTextBytes;
+    public long MaxUploadBytes => _maxUploadBytes;
+
+    // ── 루트 결정 ───────────────────────────────────────────────
+    private static string ResolveRoot(string? configured)
+    {
+        if (!string.IsNullOrWhiteSpace(configured))
+        {
+            var p = Path.IsPathRooted(configured)
+                ? configured
+                : Path.Combine(Directory.GetCurrentDirectory(), configured);
+            return Path.TrimEndingDirectorySeparator(Path.GetFullPath(p));
+        }
+
+        // 자동: 현재 디렉토리에서 위로 올라가며 .git 또는 *.sln 보유 디렉토리를 루트로
+        var dir = new DirectoryInfo(Directory.GetCurrentDirectory());
+        while (dir != null)
+        {
+            if (Directory.Exists(Path.Combine(dir.FullName, ".git")) || dir.GetFiles("*.sln").Length > 0)
+                return Path.TrimEndingDirectorySeparator(dir.FullName);
+            dir = dir.Parent;
+        }
+        return Path.TrimEndingDirectorySeparator(Directory.GetCurrentDirectory());
+    }
+
+    private static long ParseLong(string? s, long fallback)
+        => long.TryParse(s, out var v) && v > 0 ? v : fallback;
+
+    // ── 경로 안전 ───────────────────────────────────────────────
+
+    /// <summary>상대경로를 절대경로로 변환. 루트 이탈·제외 디렉토리·민감 파일이면 예외.</summary>
+    public string SafeResolve(string? relPath, bool mustExist = false)
+    {
+        var rel = (relPath ?? "").Replace('\\', '/').Trim();
+        if (rel.Contains('\0')) throw new DocBrowserException("잘못된 경로");
+        rel = rel.TrimStart('/');
+        if (rel is "." or "./") rel = "";
+
+        var candidate = Path.GetFullPath(Path.Combine(_root, rel));
+        candidate = Path.TrimEndingDirectorySeparator(candidate);
+
+        if (!IsWithinRoot(candidate))
+            throw new DocBrowserException("루트 밖 경로 접근 차단");
+
+        // 심볼릭 링크가 루트 밖을 가리키면 차단 (존재할 때만 검사)
+        var real = ResolveFinalTarget(candidate);
+        if (real != null && !IsWithinRoot(real))
+            throw new DocBrowserException("루트 밖 링크 접근 차단");
+
+        // 루트~대상 사이 모든 세그먼트 검사
+        var relToRoot = Path.GetRelativePath(_root, candidate);
+        if (relToRoot != ".")
+        {
+            var segs = relToRoot.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);
+            for (int i = 0; i < segs.Length; i++)
+            {
+                var seg = segs[i];
+                bool isLast = i == segs.Length - 1;
+                // 마지막이 아니면 반드시 디렉토리 → 디렉토리 제외 검사
+                if (!isLast && ExcludedDirs.Contains(seg))
+                    throw new DocBrowserException($"제외된 디렉토리: {seg}");
+                // 마지막 세그먼트: 디렉토리면 dir-제외, 파일이면 민감 검사
+                if (isLast)
+                {
+                    if (ExcludedDirs.Contains(seg) && Directory.Exists(candidate))
+                        throw new DocBrowserException($"제외된 디렉토리: {seg}");
+                    if (IsSensitiveFile(seg))
+                        throw new DocBrowserException("민감 파일 접근 차단");
+                }
+            }
+        }
+
+        if (mustExist && !File.Exists(candidate) && !Directory.Exists(candidate))
+            throw new DocBrowserException("대상이 존재하지 않습니다");
+
+        return candidate;
+    }
+
+    private bool IsWithinRoot(string absPath)
+    {
+        if (string.Equals(absPath, _root, PathComparison)) return true;
+        return absPath.StartsWith(_root + Path.DirectorySeparatorChar, PathComparison);
+    }
+
+    private static string? ResolveFinalTarget(string path)
+    {
+        try
+        {
+            FileSystemInfo? info = Directory.Exists(path) ? new DirectoryInfo(path)
+                                 : File.Exists(path) ? new FileInfo(path) : null;
+            if (info == null) return null;
+            var target = info.ResolveLinkTarget(returnFinalTarget: true);
+            return target == null ? null : Path.TrimEndingDirectorySeparator(target.FullName);
+        }
+        catch { return null; }
+    }
+
+    private static StringComparison PathComparison =>
+        OperatingSystem.IsWindows() ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal;
+
+    public bool IsExcludedDir(string name) => ExcludedDirs.Contains(name);
+
+    public bool IsSensitiveFile(string name)
+    {
+        foreach (var g in SensitiveGlobs)
+            if (WildcardMatch(name, g)) return true;
+        return false;
+    }
+
+    private static bool WildcardMatch(string name, string pattern)
+    {
+        var rx = "^" + Regex.Escape(pattern).Replace("\\*", ".*").Replace("\\?", ".") + "$";
+        return Regex.IsMatch(name, rx, RegexOptions.IgnoreCase);
+    }
+
+    /// <summary>절대경로 → 루트 기준 상대경로(슬래시). 루트 자신은 "".</summary>
+    public string ToRel(string absPath)
+    {
+        var rel = Path.GetRelativePath(_root, absPath);
+        return rel == "." ? "" : rel.Replace('\\', '/');
+    }
+
+    // ── 목록 ────────────────────────────────────────────────────
+
+    public List<DocEntry> List(string? relPath)
+    {
+        var abs = SafeResolve(relPath, mustExist: true);
+        if (!Directory.Exists(abs)) throw new DocBrowserException("디렉토리가 아닙니다");
+
+        var result = new List<DocEntry>();
+        var di = new DirectoryInfo(abs);
+
+        foreach (var sub in di.EnumerateDirectories())
+        {
+            if (ExcludedDirs.Contains(sub.Name)) continue;
+            if ((sub.Attributes & FileAttributes.System) != 0) continue;
+            result.Add(new DocEntry(sub.Name, ToRel(sub.FullName), true, 0, sub.LastWriteTimeUtc, ""));
+        }
+        foreach (var f in di.EnumerateFiles())
+        {
+            if (IsSensitiveFile(f.Name)) continue;
+            if ((f.Attributes & FileAttributes.System) != 0) continue;
+            result.Add(new DocEntry(f.Name, ToRel(f.FullName), false, f.Length,
+                f.LastWriteTimeUtc, f.Extension.TrimStart('.').ToLowerInvariant()));
+        }
+
+        return result
+            .OrderByDescending(e => e.IsDir)
+            .ThenBy(e => e.Name, StringComparer.OrdinalIgnoreCase)
+            .ToList();
+    }
+
+    // ── 텍스트 읽기 ─────────────────────────────────────────────
+
+    public DocTextResult ReadText(string? relPath)
+    {
+        var abs = SafeResolve(relPath, mustExist: true);
+        if (!File.Exists(abs)) throw new DocBrowserException("파일이 아닙니다");
+
+        var fi = new FileInfo(abs);
+        var cap = (int)Math.Min(fi.Length, _maxTextBytes);
+        var buf = new byte[cap];
+        int total = 0;
+        using (var fs = fi.OpenRead())
+        {
+            int r;
+            while (total < cap && (r = fs.Read(buf, total, cap - total)) > 0) total += r;
+        }
+
+        // 바이너리 휴리스틱: 앞부분에 NUL 이 있으면 텍스트 아님
+        int scan = Math.Min(total, 8000);
+        for (int i = 0; i < scan; i++)
+            if (buf[i] == 0) throw new DocBrowserException("바이너리 파일은 텍스트로 볼 수 없습니다");
+
+        var text = DecodeUtf8(buf, total);
+        return new DocTextResult(text, fi.Length > _maxTextBytes, fi.Length,
+            fi.Extension.TrimStart('.').ToLowerInvariant());
+    }
+
+    private static string DecodeUtf8(byte[] buf, int len)
+    {
+        // UTF-8 BOM 제거
+        int start = (len >= 3 && buf[0] == 0xEF && buf[1] == 0xBB && buf[2] == 0xBF) ? 3 : 0;
+        return new UTF8Encoding(false, false).GetString(buf, start, len - start);
+    }
+
+    // ── 원본 스트림 ─────────────────────────────────────────────
+
+    public DocRawResult OpenRaw(string? relPath)
+    {
+        var abs = SafeResolve(relPath, mustExist: true);
+        if (!File.Exists(abs)) throw new DocBrowserException("파일이 아닙니다");
+        var ext = Path.GetExtension(abs).TrimStart('.').ToLowerInvariant();
+        var stream = new FileStream(abs, FileMode.Open, FileAccess.Read, FileShare.Read, 64 * 1024, true);
+        return new DocRawResult(stream, ContentType(ext), Path.GetFileName(abs), ext);
+    }
+
+    public static string ContentType(string ext) => ext switch
+    {
+        "pdf" => "application/pdf",
+        "txt" or "log" or "md" or "markdown" or "csv" or "ini" or "conf" or "cfg" => "text/plain; charset=utf-8",
+        "json" => "application/json; charset=utf-8",
+        "xml" => "application/xml; charset=utf-8",
+        "html" or "htm" => "text/html; charset=utf-8",
+        "svg" => "image/svg+xml",
+        "png" => "image/png",
+        "jpg" or "jpeg" => "image/jpeg",
+        "gif" => "image/gif",
+        "webp" => "image/webp",
+        _ => "application/octet-stream",
+    };
+
+    // ── 변경 작업 (admin) ──────────────────────────────────────
+
+    public void WriteText(string? relPath, string content)
+    {
+        var abs = SafeResolve(relPath);
+        if (Directory.Exists(abs)) throw new DocBrowserException("디렉토리에는 쓸 수 없습니다");
+        var bytes = new UTF8Encoding(false).GetBytes(content ?? "");
+        if (bytes.LongLength > _maxTextBytes) throw new DocBrowserException("저장 한도를 초과했습니다");
+        var parent = Path.GetDirectoryName(abs);
+        if (parent == null || !Directory.Exists(parent)) throw new DocBrowserException("상위 폴더가 없습니다");
+        File.WriteAllBytes(abs, bytes);
+    }
+
+    public string Rename(string? fromRel, string? toRel)
+    {
+        var from = SafeResolve(fromRel, mustExist: true);
+        var to = SafeResolve(toRel);
+        if (File.Exists(to) || Directory.Exists(to)) throw new DocBrowserException("대상이 이미 존재합니다");
+        var parent = Path.GetDirectoryName(to);
+        if (parent == null || !Directory.Exists(parent)) throw new DocBrowserException("대상 상위 폴더가 없습니다");
+
+        if (Directory.Exists(from)) Directory.Move(from, to);
+        else if (File.Exists(from)) File.Move(from, to);
+        else throw new DocBrowserException("원본이 없습니다");
+        return ToRel(to);
+    }
+
+    public void Delete(string? relPath, bool recursive)
+    {
+        var abs = SafeResolve(relPath, mustExist: true);
+        if (string.Equals(abs, _root, PathComparison)) throw new DocBrowserException("루트는 삭제할 수 없습니다");
+
+        if (Directory.Exists(abs))
+        {
+            if (!recursive && Directory.EnumerateFileSystemEntries(abs).Any())
+                throw new DocBrowserException("폴더가 비어있지 않습니다 (recursive 필요)");
+            Directory.Delete(abs, recursive);
+        }
+        else if (File.Exists(abs))
+        {
+            File.Delete(abs);
+        }
+    }
+
+    public string MakeDir(string? relPath)
+    {
+        var abs = SafeResolve(relPath);
+        if (File.Exists(abs)) throw new DocBrowserException("같은 이름의 파일이 있습니다");
+        Directory.CreateDirectory(abs);
+        return ToRel(abs);
+    }
+
+    public async Task<string> SaveUploadAsync(string? dirRel, string fileName, Stream input, CancellationToken ct)
+    {
+        var safeName = Path.GetFileName(fileName ?? "");
+        if (string.IsNullOrWhiteSpace(safeName)) throw new DocBrowserException("파일명이 필요합니다");
+        if (IsSensitiveFile(safeName)) throw new DocBrowserException("이 형식은 업로드할 수 없습니다");
+
+        var dirAbs = SafeResolve(dirRel, mustExist: true);
+        if (!Directory.Exists(dirAbs)) throw new DocBrowserException("대상 폴더가 없습니다");
+
+        var abs = SafeResolve(Path.Combine(ToRel(dirAbs), safeName));
+        if (File.Exists(abs)) throw new DocBrowserException("같은 이름의 파일이 이미 있습니다");
+
+        using var fs = new FileStream(abs, FileMode.CreateNew, FileAccess.Write, FileShare.None, 64 * 1024, true);
+        var buffer = new byte[64 * 1024];
+        long total = 0;
+        int read;
+        while ((read = await input.ReadAsync(buffer.AsMemory(0, buffer.Length), ct)) > 0)
+        {
+            total += read;
+            if (total > _maxUploadBytes)
+            {
+                fs.Close();
+                try { File.Delete(abs); } catch { }
+                throw new DocBrowserException("업로드 한도를 초과했습니다");
+            }
+            await fs.WriteAsync(buffer.AsMemory(0, read), ct);
+        }
+        return ToRel(abs);
+    }
+}
diff --git a/src/Web/Controllers/DocsController.cs b/src/Web/Controllers/DocsController.cs
new file mode 100644
index 0000000..84f3317
--- /dev/null
+++ b/src/Web/Controllers/DocsController.cs
@@ -0,0 +1,172 @@
+using ExperionCrawler.Infrastructure.Docs;
+using ExperionCrawler.Infrastructure.Kb;
+using Microsoft.AspNetCore.Mvc;
+
+namespace ExperionCrawler.Web.Controllers;
+
+/// <summary>
+/// 프로젝트 폴더 문서 탐색기 API. 조회는 공개, 변경 작업(편집/이름변경/삭제/폴더/업로드)은
+/// KB admin 토큰(X-Kb-Token) 필요. 경로 안전·제외 규칙은 DocBrowserService 가 강제한다.
+/// </summary>
+[ApiController]
+[Route("api/docs")]
+public class DocsController : ControllerBase
+{
+    private readonly DocBrowserService _docs;
+    private readonly IKbAuthService _auth;
+    private readonly ILogger<DocsController> _logger;
+
+    public DocsController(DocBrowserService docs, IKbAuthService auth, ILogger<DocsController> logger)
+    {
+        _docs = docs;
+        _auth = auth;
+        _logger = logger;
+    }
+
+    private Task<bool> IsAdminAsync(CancellationToken ct)
+        => _auth.ValidateAsync(Request.Headers["X-Kb-Token"].ToString(), ct);
+
+    private IActionResult Fail(string error) => Ok(new { success = false, error });
+
+    // ── 메타/설정 ───────────────────────────────────────────────
+    [HttpGet("config")]
+    public async Task<IActionResult> Config(CancellationToken ct)
+        => Ok(new
+        {
+            success = true,
+            root = _docs.Root,
+            canManage = await IsAdminAsync(ct),
+            maxTextBytes = _docs.MaxTextBytes,
+            maxUploadBytes = _docs.MaxUploadBytes,
+        });
+
+    // ── 디렉토리 목록 ───────────────────────────────────────────
+    [HttpGet("tree")]
+    public IActionResult Tree([FromQuery] string? path)
+    {
+        try
+        {
+            var entries = _docs.List(path).Select(e => new
+            {
+                name = e.Name,
+                path = e.RelPath,
+                type = e.IsDir ? "dir" : "file",
+                size = e.Size,
+                mtime = e.ModifiedUtc,
+                ext = e.Ext,
+            });
+            return Ok(new { success = true, path = path ?? "", entries });
+        }
+        catch (DocBrowserException ex) { return Fail(ex.Message); }
+    }
+
+    // ── 텍스트 읽기 ─────────────────────────────────────────────
+    [HttpGet("text")]
+    public IActionResult Text([FromQuery] string path)
+    {
+        try
+        {
+            var r = _docs.ReadText(path);
+            return Ok(new { success = true, text = r.Text, truncated = r.Truncated, size = r.Size, ext = r.Ext });
+        }
+        catch (DocBrowserException ex) { return Fail(ex.Message); }
+    }
+
+    // ── 원본 스트림 (pdf iframe / 다운로드) ─────────────────────
+    [HttpGet("raw")]
+    public IActionResult Raw([FromQuery] string path, [FromQuery] bool download = false)
+    {
+        try
+        {
+            var r = _docs.OpenRaw(path);
+            if (download)
+                return File(r.Stream, "application/octet-stream", r.FileName);
+            return File(r.Stream, r.ContentType);   // inline (pdf 등)
+        }
+        catch (DocBrowserException ex) { return NotFound(new { success = false, error = ex.Message }); }
+    }
+
+    // ── 텍스트 저장 (admin) ─────────────────────────────────────
+    public sealed record WriteRequest(string Path, string Content);
+
+    [HttpPut("text")]
+    [RequestSizeLimit(8_000_000)]
+    public async Task<IActionResult> WriteText([FromBody] WriteRequest req, CancellationToken ct)
+    {
+        if (!await IsAdminAsync(ct)) return Unauthorized(new { success = false, error = "unauthorized" });
+        if (req == null || string.IsNullOrEmpty(req.Path)) return Fail("path required");
+        try
+        {
+            _docs.WriteText(req.Path, req.Content ?? "");
+            _logger.LogInformation("[Docs] 저장 {Path}", req.Path);
+            return Ok(new { success = true });
+        }
+        catch (DocBrowserException ex) { return Fail(ex.Message); }
+    }
+
+    // ── 이름변경/이동 (admin) ───────────────────────────────────
+    public sealed record RenameRequest(string From, string To);
+
+    [HttpPost("rename")]
+    public async Task<IActionResult> Rename([FromBody] RenameRequest req, CancellationToken ct)
+    {
+        if (!await IsAdminAsync(ct)) return Unauthorized(new { success = false, error = "unauthorized" });
+        if (req == null || string.IsNullOrEmpty(req.From) || string.IsNullOrEmpty(req.To))
+            return Fail("from/to required");
+        try
+        {
+            var newRel = _docs.Rename(req.From, req.To);
+            _logger.LogInformation("[Docs] 이름변경 {From} → {To}", req.From, newRel);
+            return Ok(new { success = true, path = newRel });
+        }
+        catch (DocBrowserException ex) { return Fail(ex.Message); }
+    }
+
+    // ── 새 폴더 (admin) ─────────────────────────────────────────
+    public sealed record MkdirRequest(string Path);
+
+    [HttpPost("mkdir")]
+    public async Task<IActionResult> Mkdir([FromBody] MkdirRequest req, CancellationToken ct)
+    {
+        if (!await IsAdminAsync(ct)) return Unauthorized(new { success = false, error = "unauthorized" });
+        if (req == null || string.IsNullOrEmpty(req.Path)) return Fail("path required");
+        try
+        {
+            var rel = _docs.MakeDir(req.Path);
+            return Ok(new { success = true, path = rel });
+        }
+        catch (DocBrowserException ex) { return Fail(ex.Message); }
+    }
+
+    // ── 삭제 (admin) ────────────────────────────────────────────
+    [HttpDelete]
+    public async Task<IActionResult> Delete([FromQuery] string path, [FromQuery] bool recursive, CancellationToken ct)
+    {
+        if (!await IsAdminAsync(ct)) return Unauthorized(new { success = false, error = "unauthorized" });
+        if (string.IsNullOrEmpty(path)) return Fail("path required");
+        try
+        {
+            _docs.Delete(path, recursive);
+            _logger.LogInformation("[Docs] 삭제 {Path} (recursive={R})", path, recursive);
+            return Ok(new { success = true });
+        }
+        catch (DocBrowserException ex) { return Fail(ex.Message); }
+    }
+
+    // ── 업로드 (admin) ──────────────────────────────────────────
+    [HttpPost("upload")]
+    [RequestSizeLimit(100_000_000)]
+    public async Task<IActionResult> Upload([FromForm] IFormFile file, [FromForm] string? path, CancellationToken ct)
+    {
+        if (!await IsAdminAsync(ct)) return Unauthorized(new { success = false, error = "unauthorized" });
+        if (file == null || file.Length == 0) return Fail("file required");
+        try
+        {
+            await using var stream = file.OpenReadStream();
+            var rel = await _docs.SaveUploadAsync(path, file.FileName, stream, ct);
+            _logger.LogInformation("[Docs] 업로드 {Path} ({Size} bytes)", rel, file.Length);
+            return Ok(new { success = true, path = rel });
+        }
+        catch (DocBrowserException ex) { return Fail(ex.Message); }
+    }
+}
diff --git a/src/Web/Program.cs b/src/Web/Program.cs
index 46ea6c5..274a260 100644
--- a/src/Web/Program.cs
+++ b/src/Web/Program.cs
@@ -140,6 +140,7 @@ builder.Services.AddSingleton<KbQdrantClient>();
 builder.Services.AddSingleton<KbStorageService>();
 builder.Services.AddSingleton<KbEmbeddingClient>();
 builder.Services.AddScoped<IKbAuthService, KbAuthService>();
+builder.Services.AddSingleton<ExperionCrawler.Infrastructure.Docs.DocBrowserService>();
 builder.Services.AddHostedService<KbStartupService>();
 builder.Services.AddHostedService<KbIngestWorker>();
 
diff --git a/src/Web/appsettings.json b/src/Web/appsettings.json
index 8b45678..a57c12f 100644
--- a/src/Web/appsettings.json
+++ b/src/Web/appsettings.json
@@ -51,6 +51,11 @@
     "WorkingDirectory": "../../mcp-server"
   },
   "PromptsDirectory": "../../prompts",
+  "DocBrowser": {
+    "Root": "",
+    "MaxTextBytes": 2097152,
+    "MaxUploadBytes": 52428800
+  },
   "Kb": {
     "QdrantUrl": "http://localhost:6333",
     "VectorSize": 768,
diff --git a/src/Web/wwwroot/css/docs.css b/src/Web/wwwroot/css/docs.css
new file mode 100644
index 0000000..dd0e9cd
--- /dev/null
+++ b/src/Web/wwwroot/css/docs.css
@@ -0,0 +1,370 @@
+/* ════════════════════════════════════════════════════════════
+   문서 탐색기 (Tab 16) — 다크 트리 + 흰색 종이 뷰어
+   ════════════════════════════════════════════════════════════ */
+
+/* 헤더 컴팩트화: 제목 위로 + 부제목을 제목 옆으로 → 문서 영역 확보 */
+#pane-docs .pane-hdr { margin-bottom: 10px; }
+#pane-docs .pane-hdr > div:first-child {
+  display: flex;
+  align-items: baseline;
+  gap: 14px;
+  flex-wrap: wrap;
+}
+#pane-docs .pane-hdr h1 { margin-bottom: 0; }
+#pane-docs .pane-hdr p { margin-bottom: 0; }
+
+.docs-layout {
+  display: flex;
+  gap: 0;
+  height: calc(100vh - 116px);
+  min-height: 560px;
+  border: 1px solid var(--bd);
+  border-radius: var(--r);
+  overflow: hidden;
+  background: var(--s1);
+}
+
+/* ── 좌: 파일 트리 패널 (다크) ─────────────────────────────── */
+.docs-tree-panel {
+  width: 300px;
+  flex-shrink: 0;
+  background: var(--s2);
+  border-right: 1px solid var(--bd);
+  display: flex;
+  flex-direction: column;
+  min-height: 0;
+}
+
+.docs-tree-toolbar {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 10px;
+  border-bottom: 1px solid var(--bd);
+}
+.docs-tree-toolbar .docs-filter {
+  flex: 1;
+  min-width: 0;
+  height: 30px;
+  font-size: 12px;
+  padding: 4px 8px;
+}
+
+.docs-root-line {
+  padding: 5px 10px;
+  font-size: 10px;
+  color: var(--t2);
+  border-bottom: 1px solid var(--bd);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  direction: rtl;        /* 긴 경로는 앞쪽을 ... 으로 */
+  text-align: left;
+}
+
+.docs-tree {
+  flex: 1;
+  overflow: auto;
+  padding: 6px 4px;
+  min-height: 0;
+}
+
+.docs-admin-bar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 8px;
+  padding: 8px 10px;
+  border-top: 1px solid var(--bd);
+}
+.docs-admin-state { font-size: 11px; color: var(--t1); }
+
+/* ── 트리 노드 ─────────────────────────────────────────────── */
+.docs-ul, .docs-children { list-style: none; margin: 0; padding: 0; }
+.docs-li { margin: 0; }
+
+.docs-node {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 4px 8px;
+  border-radius: 5px;
+  cursor: pointer;
+  color: var(--t1);
+  font-size: 12.5px;
+  user-select: none;
+  white-space: nowrap;
+}
+.docs-node:hover { background: var(--s4); color: var(--t0); }
+.docs-node.active { background: var(--ag); color: var(--blu); }
+
+.docs-node-ic {
+  flex-shrink: 0;
+  width: 16px;
+  text-align: center;
+  font-size: 11px;
+  transition: transform .15s ease;
+}
+.docs-node.is-dir > .docs-node-ic { color: var(--t2); }
+.docs-node.is-dir.open > .docs-node-ic { transform: rotate(90deg); }
+
+.docs-node-name {
+  flex: 1;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+.docs-node-size {
+  flex-shrink: 0;
+  font-family: var(--fm);
+  font-size: 9.5px;
+  color: var(--t2);
+}
+
+.docs-node-act { display: none; flex-shrink: 0; gap: 2px; }
+.docs-tree.can-manage .docs-node:hover .docs-node-act { display: flex; }
+.docs-node-act button {
+  background: transparent;
+  border: none;
+  color: var(--t2);
+  cursor: pointer;
+  font-size: 11px;
+  padding: 0 3px;
+  border-radius: 4px;
+}
+.docs-node-act button:hover { color: var(--t0); background: rgba(255,255,255,.08); }
+.docs-act-delete:hover { color: var(--red) !important; }
+
+.docs-loading, .docs-error { padding: 8px 12px; font-size: 12px; color: var(--t2); }
+.docs-error { color: var(--red); white-space: pre-wrap; }
+
+/* ── 우: 뷰어 패널 ─────────────────────────────────────────── */
+.docs-viewer-panel {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  min-width: 0;
+  min-height: 0;
+}
+
+.docs-viewer-bar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+  padding: 8px 14px;
+  background: var(--s2);
+  border-bottom: 1px solid var(--bd);
+}
+.docs-cur-path {
+  font-size: 11.5px;
+  color: var(--t1);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  direction: rtl;
+  text-align: left;
+}
+.docs-viewer-actions { display: flex; gap: 6px; flex-shrink: 0; }
+.docs-viewer-actions a.btn-b, .docs-viewer-actions a.btn-a { text-decoration: none; }
+
+/* ── 뷰어 본문: 흰색 종이 ──────────────────────────────────── */
+.docs-viewer {
+  flex: 1;
+  overflow: auto;
+  background: #ffffff;
+  color: #24292f;
+  min-height: 0;
+}
+.docs-viewer.mode-pdf { overflow: hidden; }
+
+.docs-empty {
+  height: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  color: #8b949e;
+  font-size: 14px;
+}
+
+.docs-trunc {
+  background: #fff8e6;
+  color: #7a5b00;
+  border-bottom: 1px solid #f0d98c;
+  padding: 8px 16px;
+  font-size: 12px;
+}
+
+/* 텍스트 뷰어 */
+.docs-text-pre {
+  margin: 0;
+  padding: 20px 24px;
+  font-family: var(--fm);
+  font-size: 13px;
+  line-height: 1.65;
+  color: #24292f;
+  white-space: pre-wrap;
+  word-break: break-word;
+}
+
+/* PDF 뷰어 */
+.docs-pdf-frame { width: 100%; height: 100%; border: 0; background: #fff; }
+
+/* 미지원 */
+.docs-unsupported {
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 10px;
+  color: #57606a;
+  text-align: center;
+}
+.docs-unsupported-ic { font-size: 48px; }
+.docs-unsupported .docs-muted { color: #8b949e; font-size: 12px; }
+.docs-unsupported a { margin-top: 8px; text-decoration: none; }
+
+/* ── 마크다운 본문 (GitHub-라이트 타이포) ──────────────────── */
+.md-body {
+  padding: 28px 36px;
+  max-width: 960px;
+  margin: 0 auto;
+  color: #24292f;
+  font-size: 15px;
+  line-height: 1.7;
+  word-wrap: break-word;
+}
+.md-body > *:first-child { margin-top: 0; }
+.md-body h1, .md-body h2, .md-body h3, .md-body h4, .md-body h5, .md-body h6 {
+  margin: 26px 0 14px;
+  font-weight: 700;
+  line-height: 1.3;
+  color: #1f2328;
+}
+.md-body h1 { font-size: 1.9em; padding-bottom: .3em; border-bottom: 1px solid #d8dee4; }
+.md-body h2 { font-size: 1.5em; padding-bottom: .3em; border-bottom: 1px solid #d8dee4; }
+.md-body h3 { font-size: 1.25em; }
+.md-body h4 { font-size: 1.05em; }
+.md-body p { margin: 0 0 14px; }
+.md-body a { color: #0969da; text-decoration: none; }
+.md-body a:hover { text-decoration: underline; }
+.md-body ul, .md-body ol { margin: 0 0 14px; padding-left: 2em; }
+.md-body li { margin: 3px 0; }
+.md-body li > p { margin: 4px 0; }
+.md-body blockquote {
+  margin: 0 0 14px;
+  padding: 2px 16px;
+  color: #57606a;
+  border-left: 4px solid #d0d7de;
+}
+.md-body hr { height: 1px; border: 0; background: #d8dee4; margin: 24px 0; }
+.md-body img { max-width: 100%; }
+
+/* 인라인 코드 */
+.md-body code {
+  font-family: var(--fm);
+  font-size: 85%;
+  background: rgba(175,184,193,.2);
+  padding: .2em .4em;
+  border-radius: 6px;
+}
+/* 코드블록 (highlight.js github 테마가 색 담당) */
+.md-body pre {
+  margin: 0 0 16px;
+  padding: 14px 16px;
+  background: #f6f8fa;
+  border: 1px solid #e4e8ec;
+  border-radius: 8px;
+  overflow: auto;
+  line-height: 1.5;
+}
+.md-body pre code {
+  background: transparent;
+  padding: 0;
+  font-size: 13px;
+  border-radius: 0;
+}
+
+/* GFM 표 */
+.md-body table {
+  border-collapse: collapse;
+  margin: 0 0 16px;
+  display: block;
+  width: max-content;
+  max-width: 100%;
+  overflow: auto;
+}
+.md-body th, .md-body td {
+  border: 1px solid #d0d7de;
+  padding: 6px 13px;
+}
+.md-body th { background: #f6f8fa; font-weight: 700; }
+.md-body tr:nth-child(2n) td { background: #f6f8fa; }
+
+/* 체크박스 리스트 */
+.md-body input[type="checkbox"] { margin-right: 6px; }
+
+/* mermaid */
+.md-body .mermaid { margin: 0 0 16px; text-align: center; }
+.md-body .mermaid svg { max-width: 100%; height: auto; }
+
+/* ── 편집 모드 ─────────────────────────────────────────────── */
+.docs-viewer.mode-edit { background: #ffffff; }
+.docs-edit-wrap {
+  display: flex;
+  height: 100%;
+  min-height: 0;
+}
+.docs-edit-ta {
+  flex: 1;
+  border: 0;
+  outline: none;
+  resize: none;
+  padding: 20px 24px;
+  font-family: var(--fm);
+  font-size: 13px;
+  line-height: 1.65;
+  color: #24292f;
+  background: #ffffff;
+  min-width: 0;
+}
+.docs-viewer.mode-edit.is-md .docs-edit-ta {
+  border-right: 1px solid #d8dee4;
+  flex: 0 0 50%;
+}
+.docs-edit-prev {
+  flex: 1;
+  overflow: auto;
+  padding: 20px 28px;
+  max-width: none;
+  margin: 0;
+  background: #fbfcfd;
+  min-width: 0;
+}
+
+/* ── 토스트 ────────────────────────────────────────────────── */
+.docs-toast {
+  position: fixed;
+  bottom: 24px;
+  left: 50%;
+  transform: translateX(-50%) translateY(20px);
+  background: var(--s3);
+  color: var(--t0);
+  border: 1px solid var(--bd2);
+  padding: 10px 18px;
+  border-radius: 8px;
+  font-size: 13px;
+  box-shadow: 0 8px 24px rgba(0,0,0,.4);
+  opacity: 0;
+  pointer-events: none;
+  transition: opacity .2s ease, transform .2s ease;
+  z-index: 1000;
+}
+.docs-toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
+
+/* 좁은 화면 */
+@media (max-width: 900px) {
+  .docs-tree-panel { width: 200px; }
+  .docs-viewer.mode-edit.is-md .docs-edit-ta { flex: 0 0 100%; }
+  .docs-edit-prev { display: none; }
+}
diff --git a/src/Web/wwwroot/css/style.css b/src/Web/wwwroot/css/style.css
index 6cfd0df..d70a517 100644
--- a/src/Web/wwwroot/css/style.css
+++ b/src/Web/wwwroot/css/style.css
@@ -68,10 +68,11 @@ html, body { height: 100%; background: var(--s0); color: var(--t1); font-family:
 }
 
 /* nav */
-.nav { list-style: none; padding: 14px 10px; flex: 1; display: flex; flex-direction: column; gap: 3px; }
+.nav { list-style: none; padding: 14px 10px; flex: 1; min-height: 0; overflow-y: auto; display: flex; flex-direction: column; gap: 3px; }
 
 .nav-item {
   display: flex; align-items: center; gap: 10px;
+  flex-shrink: 0;
   padding: 10px 12px; border-radius: var(--r);
   cursor: pointer; transition: all var(--tr);
   color: var(--t2); font-size: 13px; font-weight: 600;
diff --git a/src/Web/wwwroot/index.html b/src/Web/wwwroot/index.html
index d240288..33f9d8d 100644
--- a/src/Web/wwwroot/index.html
+++ b/src/Web/wwwroot/index.html
@@ -6,6 +6,7 @@
   <title>ExperionCrawler</title>
   <link rel="stylesheet" href="/css/style.css"/>
   <link rel="stylesheet" href="/lib/uPlot.min.css"/>
+  <link rel="stylesheet" href="/css/docs.css"/>
 </head>
 <body>
 <div class="shell">
@@ -92,6 +93,10 @@
         <span class="ni">15</span>
         <span class="nl">OPC UA Write</span>
       </li>
+      <li class="nav-item" data-tab="docs">
+        <span class="ni">16</span>
+        <span class="nl">문서 탐색기</span>
+      </li>
     </ul>
 
     <div class="sb-foot">
@@ -1623,6 +1628,49 @@
       <div id="wr-log" class="logbox hidden"></div>
     </section>
 
+    <!-- ══════════════════════════════════════════════════════
+         16  문서 탐색기
+    ═══════════════════════════════════════════════════════ -->
+    <section class="pane" id="pane-docs">
+      <header class="pane-hdr">
+        <div>
+          <h1>문서 탐색기</h1>
+          <p>프로젝트 폴더의 문서를 직접 보고 편집합니다. 뷰어: txt · md · pdf · 그 외 다운로드.</p>
+        </div>
+        <div class="pane-tag">DOCS</div>
+      </header>
+
+      <div class="docs-layout">
+        <!-- 좌: 파일 트리 -->
+        <aside class="docs-tree-panel">
+          <div class="docs-tree-toolbar">
+            <button class="btn-b btn-sm" onclick="docsRefresh()" title="새로고침">⟳</button>
+            <input id="docs-filter" class="inp docs-filter" placeholder="이름 필터…" oninput="docsApplyFilter()"/>
+            <button class="btn-b btn-sm docs-admin-only" id="docs-mkdir-btn" onclick="docsMkdirPrompt()" title="새 폴더" hidden>📁＋</button>
+            <button class="btn-b btn-sm docs-admin-only" id="docs-upload-btn" onclick="docsUploadPrompt()" title="업로드" hidden>⤴</button>
+            <input type="file" id="docs-upload-input" hidden onchange="docsUploadDo()"/>
+          </div>
+          <div class="docs-root-line" title="탐색 루트"><span id="docs-root-label" class="mono"></span></div>
+          <div id="docs-tree" class="docs-tree"></div>
+          <div class="docs-admin-bar">
+            <span id="docs-admin-state" class="docs-admin-state">🔒 읽기 전용</span>
+            <button class="btn-b btn-sm" id="docs-unlock-btn" onclick="docsUnlock()">관리 잠금해제</button>
+          </div>
+        </aside>
+
+        <!-- 우: 뷰어 -->
+        <div class="docs-viewer-panel">
+          <div class="docs-viewer-bar">
+            <span id="docs-cur-path" class="docs-cur-path mono">파일을 선택하세요</span>
+            <div class="docs-viewer-actions" id="docs-viewer-actions"></div>
+          </div>
+          <div id="docs-viewer" class="docs-viewer">
+            <div class="docs-empty">← 왼쪽에서 문서를 선택하세요</div>
+          </div>
+        </div>
+      </div>
+    </section>
+
   </main>
   </div>
 </div>
@@ -1708,5 +1756,6 @@
 <script src="/lib/uPlot.iife.min.js"></script>
 <script src="/js/xlsx.full.min.js"></script>
 <script src="/js/app.js"></script>
+<script src="/js/docs.js"></script>
 </body>
 </html>
diff --git a/src/Web/wwwroot/js/app.js b/src/Web/wwwroot/js/app.js
index 1838c85..6837422 100644
--- a/src/Web/wwwroot/js/app.js
+++ b/src/Web/wwwroot/js/app.js
@@ -15,6 +15,7 @@ document.querySelectorAll('.nav-item').forEach(item => {
     if (tab === 'opcsvr') srvLoad();
     if (tab === 't2s') t2sInitMode();
     if (tab === 'fast') fastSessionsLoad();
+    if (tab === 'docs') docsInit();
   });
 });
 
diff --git a/src/Web/wwwroot/js/docs.js b/src/Web/wwwroot/js/docs.js
new file mode 100644
index 0000000..b4561a9
--- /dev/null
+++ b/src/Web/wwwroot/js/docs.js
@@ -0,0 +1,571 @@
+/* ════════════════════════════════════════════════════════════════
+   문서 탐색기 (Tab 16) — 프로젝트 폴더 트리 탐색 + txt/md/pdf 뷰어 + 인라인 편집/관리
+   백엔드: /api/docs/*  (변경 작업은 X-Kb-Token admin)
+   esc() / kbToken 은 app.js(선로딩) 전역 재사용
+   ════════════════════════════════════════════════════════════════ */
+
+const DOCS_TEXT_EXT = ['txt', 'log', 'text'];
+const DOCS_MD_EXT = ['md', 'markdown'];
+
+const docsState = {
+  inited: false,
+  canManage: false,
+  root: '',
+  curFile: null,   // { path, ext }
+  editing: false,
+};
+
+/* ── 진입 ──────────────────────────────────────────────────── */
+async function docsInit() {
+  await docsLoadConfig();
+  if (!docsState.inited) {
+    docsState.inited = true;
+    document.getElementById('docs-tree').addEventListener('click', docsTreeClick);
+    await docsRefresh();
+  }
+}
+
+async function docsLoadConfig() {
+  try {
+    const r = await fetch('/api/docs/config', { headers: docsHeaders() });
+    const d = await r.json();
+    docsState.canManage = !!d.canManage;
+    docsState.root = d.root || '';
+    document.getElementById('docs-root-label').textContent = d.root || '';
+    docsUpdateAdminUi();
+  } catch (e) { /* noop */ }
+}
+
+/* ── 인증 헤더 (KB admin 토큰 재사용) ───────────────────────── */
+function docsToken() { return sessionStorage.getItem('kbToken') || ''; }
+function docsHeaders(extra) {
+  const h = extra || {};
+  const t = docsToken();
+  if (t) h['X-Kb-Token'] = t;
+  return h;
+}
+
+/* ── 관리 UI 토글 ──────────────────────────────────────────── */
+function docsUpdateAdminUi() {
+  const on = docsState.canManage;
+  document.getElementById('docs-mkdir-btn').hidden = !on;
+  document.getElementById('docs-upload-btn').hidden = !on;
+  document.getElementById('docs-tree').classList.toggle('can-manage', on);
+  document.getElementById('docs-admin-state').textContent = on ? '🔓 관리 가능' : '🔒 읽기 전용';
+  document.getElementById('docs-unlock-btn').textContent = on ? '잠금' : '관리 잠금해제';
+  if (docsState.curFile) docsRenderViewerActions();
+}
+
+async function docsUnlock() {
+  if (docsState.canManage) {
+    try { await fetch('/api/kb/auth/logout', { method: 'POST', headers: docsHeaders() }); } catch (e) {}
+    sessionStorage.removeItem('kbToken');
+    try { kbToken = ''; } catch (e) {}
+    await docsLoadConfig();
+    return;
+  }
+  const pw = prompt('관리자 비밀번호');
+  if (!pw) return;
+  try {
+    const r = await fetch('/api/kb/auth/login', {
+      method: 'POST', headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ password: pw }),
+    });
+    const d = await r.json();
+    if (!d.success) { alert('로그인 실패: ' + (d.error || '')); return; }
+    sessionStorage.setItem('kbToken', d.token);
+    try { kbToken = d.token; } catch (e) {}
+    await docsLoadConfig();
+    docsToast('관리 잠금해제됨');
+  } catch (e) { alert('로그인 오류: ' + e.message); }
+}
+
+/* ── 트리 ──────────────────────────────────────────────────── */
+async function docsFetchTree(path) {
+  const r = await fetch('/api/docs/tree?path=' + encodeURIComponent(path || ''), { headers: docsHeaders() });
+  const d = await r.json();
+  if (!d.success) throw new Error(d.error || '목록 조회 실패');
+  return d.entries;
+}
+
+async function docsRefresh() {
+  const host = document.getElementById('docs-tree');
+  host.innerHTML = '<div class="docs-loading">불러오는 중…</div>';
+  try {
+    const entries = await docsFetchTree('');
+    const ul = document.createElement('ul');
+    ul.className = 'docs-ul';
+    docsRenderInto(ul, entries, 0);
+    host.innerHTML = '';
+    host.appendChild(ul);
+    docsApplyFilter();
+  } catch (e) {
+    host.innerHTML = '<div class="docs-error">' + esc(e.message) + '</div>';
+  }
+}
+
+function docsRenderInto(ul, entries, depth) {
+  for (const e of entries) {
+    const li = document.createElement('li');
+    li.className = 'docs-li';
+    li.appendChild(docsNodeRow(e, depth));
+    if (e.type === 'dir') {
+      const kids = document.createElement('ul');
+      kids.className = 'docs-children';
+      kids.hidden = true;
+      li.appendChild(kids);
+    }
+    ul.appendChild(li);
+  }
+}
+
+function docsNodeRow(entry, depth) {
+  const row = document.createElement('div');
+  row.className = 'docs-node ' + (entry.type === 'dir' ? 'is-dir' : 'is-file');
+  row.style.paddingLeft = (8 + depth * 14) + 'px';
+  row.dataset.path = entry.path;
+  row.dataset.type = entry.type;
+  row.dataset.name = (entry.name || '').toLowerCase();
+  row.dataset.ext = entry.ext || '';
+  row.dataset.depth = depth;
+
+  const ic = entry.type === 'dir' ? '▸' : docsFileIcon(entry.ext);
+  const size = entry.type === 'file' ? `<span class="docs-node-size">${docsFmtSize(entry.size)}</span>` : '';
+  const acts = `<span class="docs-node-act">
+      <button class="docs-act-rename" title="이름변경">✎</button>
+      <button class="docs-act-delete" title="삭제">🗑</button>
+    </span>`;
+  row.innerHTML =
+    `<span class="docs-node-ic">${ic}</span>` +
+    `<span class="docs-node-name">${esc(entry.name)}</span>` +
+    size + acts;
+  return row;
+}
+
+async function docsTreeClick(ev) {
+  const renameBtn = ev.target.closest('.docs-act-rename');
+  const deleteBtn = ev.target.closest('.docs-act-delete');
+  const row = ev.target.closest('.docs-node');
+  if (!row) return;
+
+  if (renameBtn) { ev.stopPropagation(); return docsRenamePrompt(row.dataset.path); }
+  if (deleteBtn) { ev.stopPropagation(); return docsDeletePrompt(row.dataset.path, row.dataset.type); }
+
+  if (row.dataset.type === 'dir') return docsToggleDir(row);
+  // 파일
+  document.querySelectorAll('#docs-tree .docs-node.active').forEach(n => n.classList.remove('active'));
+  row.classList.add('active');
+  docsOpenPath(row.dataset.path);
+}
+
+async function docsToggleDir(row) {
+  const li = row.parentElement;
+  const kids = li.querySelector(':scope > .docs-children');
+  if (!kids) return;
+  if (kids.hidden) {
+    if (kids.dataset.loaded !== '1') {
+      kids.innerHTML = '<li class="docs-loading">…</li>';
+      try {
+        const entries = await docsFetchTree(row.dataset.path);
+        kids.innerHTML = '';
+        docsRenderInto(kids, entries, (+row.dataset.depth) + 1);
+        kids.dataset.loaded = '1';
+        docsApplyFilter();
+      } catch (e) {
+        kids.innerHTML = '<li class="docs-error">' + esc(e.message) + '</li>';
+      }
+    }
+    kids.hidden = false;
+    row.classList.add('open');
+  } else {
+    kids.hidden = true;
+    row.classList.remove('open');
+  }
+}
+
+/* ── 파일 열기 / 뷰어 디스패치 ─────────────────────────────── */
+function docsOpenPath(path) {
+  const ext = (path.split('.').pop() || '').toLowerCase();
+  docsState.curFile = { path, ext };
+  docsState.editing = false;
+  document.getElementById('docs-cur-path').textContent = path;
+  docsRenderViewerActions();
+  if (DOCS_MD_EXT.includes(ext)) docsViewMarkdown(path);
+  else if (ext === 'pdf') docsViewPdf(path);
+  else if (DOCS_TEXT_EXT.includes(ext)) docsViewText(path);
+  else docsViewUnsupported(path, ext);
+}
+
+async function docsFetchText(path) {
+  const r = await fetch('/api/docs/text?path=' + encodeURIComponent(path), { headers: docsHeaders() });
+  const d = await r.json();
+  if (!d.success) throw new Error(d.error || '파일 읽기 실패');
+  return d;
+}
+
+function docsViewer() { return document.getElementById('docs-viewer'); }
+function docsViewerError(err) {
+  docsViewer().className = 'docs-viewer';
+  docsViewer().innerHTML = '<div class="docs-error">' + esc(err.message || String(err)) + '</div>';
+}
+function docsTruncBanner(size) {
+  const b = document.createElement('div');
+  b.className = 'docs-trunc';
+  b.textContent = `⚠ 파일이 커서 일부만 표시합니다 (전체 ${docsFmtSize(size)}). 다운로드로 전체 확인하세요.`;
+  return b;
+}
+
+async function docsViewText(path) {
+  const v = docsViewer();
+  v.className = 'docs-viewer mode-text';
+  v.innerHTML = '<div class="docs-loading">불러오는 중…</div>';
+  try {
+    const d = await docsFetchText(path);
+    v.innerHTML = '';
+    if (d.truncated) v.appendChild(docsTruncBanner(d.size));
+    const pre = document.createElement('pre');
+    pre.className = 'docs-text-pre';
+    pre.textContent = d.text;
+    v.appendChild(pre);
+  } catch (e) { docsViewerError(e); }
+}
+
+function docsViewPdf(path) {
+  const v = docsViewer();
+  v.className = 'docs-viewer mode-pdf';
+  const src = '/api/docs/raw?path=' + encodeURIComponent(path);
+  v.innerHTML = `<iframe class="docs-pdf-frame" src="${src}"></iframe>`;
+}
+
+async function docsViewMarkdown(path) {
+  const v = docsViewer();
+  v.className = 'docs-viewer mode-md';
+  v.innerHTML = '<div class="docs-loading">렌더링 준비 중…</div>';
+  try {
+    await docsEnsureMdLibs();
+    const d = await docsFetchText(path);
+    v.innerHTML = '';
+    if (d.truncated) v.appendChild(docsTruncBanner(d.size));
+    const body = document.createElement('div');
+    body.className = 'md-body';
+    v.appendChild(body);
+    docsRenderMarkdownInto(body, d.text);
+  } catch (e) { docsViewerError(e); }
+}
+
+function docsViewUnsupported(path, ext) {
+  const v = docsViewer();
+  v.className = 'docs-viewer mode-unsupported';
+  v.innerHTML = `<div class="docs-unsupported">
+    <div class="docs-unsupported-ic">${docsFileIcon(ext)}</div>
+    <p><b>.${esc(ext || '?')}</b> 형식은 미리보기를 지원하지 않습니다.</p>
+    <p class="docs-muted">지원 뷰어: txt · md · pdf</p>
+    <a class="btn-a btn-sm" href="/api/docs/raw?path=${encodeURIComponent(path)}&download=true">⬇ 다운로드</a>
+  </div>`;
+}
+
+/* ── 마크다운 렌더 파이프라인 ──────────────────────────────── */
+function docsRenderMarkdownInto(el, text) {
+  const rawHtml = marked.parse(text, { gfm: true, breaks: false });
+  el.innerHTML = DOMPurify.sanitize(rawHtml, { ADD_TAGS: ['details', 'summary'], ADD_ATTR: ['target'] });
+  docsExternalLinks(el);
+  docsExtractMermaid(el);   // mermaid 코드블록 → div.mermaid (highlight 전)
+  docsHighlight(el);
+  docsRenderMath(el);
+  docsRunMermaid(el);
+}
+
+function docsExternalLinks(el) {
+  el.querySelectorAll('a[href]').forEach(a => {
+    const href = a.getAttribute('href') || '';
+    if (/^https?:/i.test(href)) {
+      a.target = '_blank'; a.rel = 'noopener noreferrer';
+    } else if (href && !href.startsWith('#') && docsState.curFile) {
+      // 상대 링크 → 탐색기 내에서 열기
+      const rel = docsResolveRel(docsState.curFile.path, href);
+      if (rel != null) {
+        a.addEventListener('click', (ev) => { ev.preventDefault(); docsOpenPath(rel); });
+      }
+    }
+  });
+}
+
+function docsResolveRel(basePath, href) {
+  try {
+    const clean = href.split('#')[0].split('?')[0];
+    if (!clean) return null;
+    const baseDir = basePath.includes('/') ? basePath.slice(0, basePath.lastIndexOf('/')) : '';
+    const parts = (baseDir ? baseDir.split('/') : []).concat(clean.split('/'));
+    const stack = [];
+    for (const p of parts) {
+      if (p === '' || p === '.') continue;
+      if (p === '..') stack.pop();
+      else stack.push(p);
+    }
+    return stack.join('/');
+  } catch (e) { return null; }
+}
+
+function docsExtractMermaid(el) {
+  el.querySelectorAll('code.language-mermaid').forEach(code => {
+    const div = document.createElement('div');
+    div.className = 'mermaid';
+    div.textContent = code.textContent;
+    (code.closest('pre') || code).replaceWith(div);
+  });
+}
+
+function docsHighlight(el) {
+  if (typeof hljs === 'undefined') return;
+  el.querySelectorAll('pre code').forEach(c => { try { hljs.highlightElement(c); } catch (e) {} });
+}
+
+function docsRenderMath(el) {
+  if (typeof renderMathInElement === 'undefined') return;
+  try {
+    renderMathInElement(el, {
+      delimiters: [
+        { left: '$$', right: '$$', display: true },
+        { left: '$', right: '$', display: false },
+        { left: '\\[', right: '\\]', display: true },
+        { left: '\\(', right: '\\)', display: false },
+      ],
+      throwOnError: false,
+    });
+  } catch (e) {}
+}
+
+async function docsRunMermaid(el) {
+  const nodes = el.querySelectorAll('.mermaid');
+  if (!nodes.length || typeof mermaid === 'undefined') return;
+  try { await mermaid.run({ nodes }); } catch (e) { /* 실패 시 원문 텍스트 유지 */ }
+}
+
+/* ── 라이브러리 lazy 로더 (md 첫 진입 시 1회) ──────────────── */
+let _docsMdLibs = null;
+function docsLoadScript(src) {
+  return new Promise((res, rej) => {
+    const s = document.createElement('script');
+    s.src = src; s.onload = res; s.onerror = () => rej(new Error('스크립트 로드 실패: ' + src));
+    document.head.appendChild(s);
+  });
+}
+function docsLoadCss(href) {
+  return new Promise((res) => {
+    const l = document.createElement('link');
+    l.rel = 'stylesheet'; l.href = href; l.onload = res; l.onerror = res;
+    document.head.appendChild(l);
+  });
+}
+function docsEnsureMdLibs() {
+  if (_docsMdLibs) return _docsMdLibs;
+  _docsMdLibs = (async () => {
+    docsLoadCss('/lib/highlight-github.min.css');
+    docsLoadCss('/lib/katex/katex.min.css');
+    await docsLoadScript('/lib/marked.min.js');
+    await docsLoadScript('/lib/purify.min.js');
+    await docsLoadScript('/lib/highlight.min.js');
+    await docsLoadScript('/lib/katex/katex.min.js');
+    await docsLoadScript('/lib/katex/auto-render.min.js');
+    await docsLoadScript('/lib/mermaid.min.js');
+    try { mermaid.initialize({ startOnLoad: false, theme: 'default', securityLevel: 'strict' }); } catch (e) {}
+  })();
+  return _docsMdLibs;
+}
+
+/* ── 뷰어 툴바 액션 ────────────────────────────────────────── */
+function docsRenderViewerActions() {
+  const host = document.getElementById('docs-viewer-actions');
+  const f = docsState.curFile;
+  if (!f) { host.innerHTML = ''; return; }
+  const isText = DOCS_TEXT_EXT.includes(f.ext) || DOCS_MD_EXT.includes(f.ext);
+  let h = '';
+  if (docsState.editing) {
+    h += `<button class="btn-a btn-sm" onclick="docsEditSave()">💾 저장</button>`;
+    h += `<button class="btn-b btn-sm" onclick="docsEditCancel()">취소</button>`;
+  } else {
+    if (isText && docsState.canManage) h += `<button class="btn-b btn-sm" onclick="docsEditStart()">✎ 편집</button>`;
+    h += `<a class="btn-b btn-sm" href="/api/docs/raw?path=${encodeURIComponent(f.path)}&download=true">⬇ 다운로드</a>`;
+  }
+  host.innerHTML = h;
+}
+
+/* ── 인라인 편집 ───────────────────────────────────────────── */
+async function docsEditStart() {
+  const f = docsState.curFile;
+  if (!f || !docsState.canManage) return;
+  let d;
+  try { d = await docsFetchText(f.path); } catch (e) { alert(e.message); return; }
+  docsState.editing = true;
+  docsRenderViewerActions();
+  const isMd = DOCS_MD_EXT.includes(f.ext);
+  const v = docsViewer();
+  v.className = 'docs-viewer mode-edit' + (isMd ? ' is-md' : '');
+  v.innerHTML =
+    `<div class="docs-edit-wrap">
+       <textarea id="docs-edit-ta" class="docs-edit-ta" spellcheck="false"></textarea>
+       ${isMd ? '<div id="docs-edit-prev" class="md-body docs-edit-prev"></div>' : ''}
+     </div>`;
+  const ta = document.getElementById('docs-edit-ta');
+  ta.value = d.text;
+  if (isMd) {
+    await docsEnsureMdLibs();
+    const prev = document.getElementById('docs-edit-prev');
+    const upd = docsDebounce(() => docsRenderMarkdownInto(prev, ta.value), 250);
+    ta.addEventListener('input', upd);
+    docsRenderMarkdownInto(prev, ta.value);
+  }
+}
+
+async function docsEditSave() {
+  const f = docsState.curFile;
+  const ta = document.getElementById('docs-edit-ta');
+  if (!f || !ta) return;
+  try {
+    const r = await fetch('/api/docs/text', {
+      method: 'PUT',
+      headers: docsHeaders({ 'Content-Type': 'application/json' }),
+      body: JSON.stringify({ path: f.path, content: ta.value }),
+    });
+    const d = await r.json();
+    if (!d.success) { alert('저장 실패: ' + (d.error || r.status)); return; }
+    docsState.editing = false;
+    docsOpenPath(f.path);
+    docsToast('저장됨');
+  } catch (e) { alert('저장 오류: ' + e.message); }
+}
+
+function docsEditCancel() {
+  docsState.editing = false;
+  if (docsState.curFile) docsOpenPath(docsState.curFile.path);
+}
+
+/* ── 관리: 새 폴더 / 업로드 / 이름변경 / 삭제 ──────────────── */
+async function docsMkdirPrompt() {
+  const path = prompt('새 폴더 경로 (루트 기준, 예: docs/notes)');
+  if (!path) return;
+  try {
+    const r = await fetch('/api/docs/mkdir', {
+      method: 'POST', headers: docsHeaders({ 'Content-Type': 'application/json' }),
+      body: JSON.stringify({ path }),
+    });
+    const d = await r.json();
+    if (!d.success) { alert('실패: ' + (d.error || '')); return; }
+    await docsRefresh();
+    docsToast('폴더 생성됨');
+  } catch (e) { alert(e.message); }
+}
+
+function docsUploadPrompt() {
+  document.getElementById('docs-upload-input').click();
+}
+
+async function docsUploadDo() {
+  const input = document.getElementById('docs-upload-input');
+  const file = input.files && input.files[0];
+  if (!file) return;
+  const dir = prompt('업로드할 대상 폴더 (루트 기준, 비우면 루트)', '') || '';
+  const fd = new FormData();
+  fd.append('file', file);
+  fd.append('path', dir);
+  try {
+    const r = await fetch('/api/docs/upload', { method: 'POST', headers: docsHeaders(), body: fd });
+    const d = await r.json();
+    input.value = '';
+    if (!d.success) { alert('업로드 실패: ' + (d.error || '')); return; }
+    await docsRefresh();
+    docsToast('업로드됨: ' + d.path);
+  } catch (e) { input.value = ''; alert(e.message); }
+}
+
+async function docsRenamePrompt(path) {
+  if (!docsState.canManage) return;
+  const next = prompt('새 경로 (루트 기준)', path);
+  if (!next || next === path) return;
+  try {
+    const r = await fetch('/api/docs/rename', {
+      method: 'POST', headers: docsHeaders({ 'Content-Type': 'application/json' }),
+      body: JSON.stringify({ from: path, to: next }),
+    });
+    const d = await r.json();
+    if (!d.success) { alert('실패: ' + (d.error || '')); return; }
+    await docsRefresh();
+    docsToast('이름 변경됨');
+  } catch (e) { alert(e.message); }
+}
+
+async function docsDeletePrompt(path, type) {
+  if (!docsState.canManage) return;
+  const isDir = type === 'dir';
+  const msg = isDir
+    ? `폴더와 그 안의 모든 내용을 삭제합니다:\n${path}\n\n되돌릴 수 없습니다. 계속할까요?`
+    : `파일을 삭제합니다:\n${path}\n\n계속할까요?`;
+  if (!confirm(msg)) return;
+  try {
+    const url = '/api/docs?path=' + encodeURIComponent(path) + (isDir ? '&recursive=true' : '');
+    const r = await fetch(url, { method: 'DELETE', headers: docsHeaders() });
+    const d = await r.json();
+    if (!d.success) { alert('삭제 실패: ' + (d.error || '')); return; }
+    if (docsState.curFile && docsState.curFile.path === path) {
+      docsState.curFile = null;
+      document.getElementById('docs-cur-path').textContent = '파일을 선택하세요';
+      document.getElementById('docs-viewer-actions').innerHTML = '';
+      docsViewer().className = 'docs-viewer';
+      docsViewer().innerHTML = '<div class="docs-empty">← 왼쪽에서 문서를 선택하세요</div>';
+    }
+    await docsRefresh();
+    docsToast('삭제됨');
+  } catch (e) { alert(e.message); }
+}
+
+/* ── 필터 ──────────────────────────────────────────────────── */
+function docsApplyFilter() {
+  const q = (document.getElementById('docs-filter').value || '').toLowerCase().trim();
+  document.querySelectorAll('#docs-tree .docs-li').forEach(li => {
+    const row = li.querySelector(':scope > .docs-node');
+    if (!row) return;
+    if (row.dataset.type === 'dir') { li.style.display = ''; return; }
+    li.style.display = (!q || row.dataset.name.includes(q)) ? '' : 'none';
+  });
+}
+
+/* ── 유틸 ──────────────────────────────────────────────────── */
+function docsFmtSize(n) {
+  if (n == null) return '';
+  if (n < 1024) return n + ' B';
+  if (n < 1024 * 1024) return (n / 1024).toFixed(1) + ' KB';
+  return (n / 1024 / 1024).toFixed(1) + ' MB';
+}
+
+function docsFileIcon(ext) {
+  ext = (ext || '').toLowerCase();
+  if (DOCS_MD_EXT.includes(ext)) return '📝';
+  if (ext === 'pdf') return '📕';
+  if (DOCS_TEXT_EXT.includes(ext)) return '📄';
+  if (['png', 'jpg', 'jpeg', 'gif', 'svg', 'webp'].includes(ext)) return '🖼';
+  if (['xlsx', 'xls', 'csv'].includes(ext)) return '📊';
+  if (['docx', 'doc'].includes(ext)) return '📘';
+  if (['json', 'xml', 'yaml', 'yml'].includes(ext)) return '🔧';
+  if (['dxf', 'dwg'].includes(ext)) return '📐';
+  return '📄';
+}
+
+function docsDebounce(fn, ms) {
+  let t;
+  return function (...a) { clearTimeout(t); t = setTimeout(() => fn.apply(this, a), ms); };
+}
+
+let _docsToastTimer = null;
+function docsToast(msg) {
+  let el = document.getElementById('docs-toast');
+  if (!el) {
+    el = document.createElement('div');
+    el.id = 'docs-toast';
+    el.className = 'docs-toast';
+    document.body.appendChild(el);
+  }
+  el.textContent = msg;
+  el.classList.add('show');
+  clearTimeout(_docsToastTimer);
+  _docsToastTimer = setTimeout(() => el.classList.remove('show'), 2200);
+}