M0: remote access server - Kestrel embedded (token auth/pair/queue API/library/range streaming/web companion zero-install), QR pairing window, DownloadQueueAdapter, auto-start+palette commands. Server E2E green (102 tests)

VideoDownloader.Server/MediaLibrary.cs

@@ -0,0 +1,45 @@
+using System.Security.Cryptography;
+
+namespace VideoDownloader.Server;
+
+/// <summary>저장 폴더 미디어 라이브러리: 파일 나열/조회(ID = SHA-256 경로 해시 12자).</summary>
+public static class MediaLibrary
+{
+    private static readonly string[] VideoExts = { ".mp4", ".mkv", ".webm", ".ts", ".mov", ".m4v", ".avi", ".mp3", ".m4a" };
+
+    public static List<LibraryItemDto> List(string folder)
+    {
+        var result = new List<LibraryItemDto>();
+        try
+        {
+            if (string.IsNullOrEmpty(folder) || !Directory.Exists(folder)) return result;
+            foreach (var f in Directory.EnumerateFiles(folder).OrderByDescending(f => File.GetLastWriteTimeUtc(f)))
+            {
+                var ext = Path.GetExtension(f).ToLowerInvariant();
+                if (!VideoExts.Contains(ext)) continue;
+                var fi = new FileInfo(f);
+                result.Add(new LibraryItemDto(IdOf(f), fi.Name, fi.Length, fi.LastWriteTimeUtc));
+            }
+        }
+        catch { }
+        return result;
+    }
+
+    public static (string FullPath, string FileName)? Find(string folder, string id)
+    {
+        try
+        {
+            if (string.IsNullOrEmpty(folder) || !Directory.Exists(folder)) return null;
+            foreach (var f in Directory.EnumerateFiles(folder))
+                if (IdOf(f) == id) return (f, Path.GetFileName(f));
+        }
+        catch { }
+        return null;
+    }
+
+    private static string IdOf(string path)
+    {
+        var hash = SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(Path.GetFullPath(path)));
+        return Convert.ToHexString(hash)[..12].ToLowerInvariant();
+    }
+}