feat(cms): retire legacy single-track forms; route single-track edit into BatchEdit (8.M)

DeepDrftManager/Components/Pages/Tracks/BatchEdit.razor

@@ -1,4 +1,5 @@
 @page "/tracks/album/{AlbumName}/edit"
+@page "/tracks/{TrackId:long}/edit"
 @using System.Security.Claims
 @using DeepDrftManager.Services
 @using DeepDrftModels.DTOs
@@ -111,8 +112,15 @@
     // 1 GB ceiling matches DeepDrftAPI's per-request limit on api/track/upload.
     private const long MaxUploadBytes = 1_073_741_824L;
 
+    // Release-title addressing (Album-mode batch Edit): loads the whole release by title.
     [Parameter] public string AlbumName { get; set; } = string.Empty;
 
+    // Track-id addressing (Track-mode per-row Edit, §8.M): loads the addressed track's parent
+    // release and pre-selects that track's row, so editing a single Cut track lands the admin on
+    // the track they clicked rather than on the release with no row context. Null for the
+    // release-title route. The two routes are mutually exclusive — only one segment binds.
+    [Parameter] public long? TrackId { get; set; }
+
     private List<BatchRowModel> _tracks = new();
     private int _selectedIndex = -1;
     private bool _loading = true;
@@ -154,12 +162,35 @@
 
     protected override async Task OnInitializedAsync()
     {
+        // Track-addressed entry (§8.M): resolve the addressed track to its parent release title,
+        // then fall through to the shared release-load path below. The clicked track's id is held
+        // for row pre-selection once the list is built.
+        var albumName = AlbumName;
+        if (TrackId is { } trackId)
+        {
+            var trackResult = await CmsTrackService.GetByIdAsync(trackId);
+            if (!trackResult.Success || trackResult.Value is not { } track)
+            {
+                _loadError = trackResult.Messages.FirstOrDefault()?.Message ?? "Track not found.";
+                _loading = false;
+                return;
+            }
+
+            albumName = track.Release?.Title;
+            if (string.IsNullOrEmpty(albumName))
+            {
+                _loadError = "This track has no parent release to edit.";
+                _loading = false;
+                return;
+            }
+        }
+
         // A single page of 100 covers the full release (albums are small — same assumption as
         // CmsAlbumBrowser). Sorted by track number so list order matches the saved ordinals.
         var result = await CmsTrackService.GetPagedAsync(
             page: 1, pageSize: 100,
             sortColumn: "TrackNumber", sortDescending: false,
-            album: AlbumName);
+            album: albumName);
 
         if (!result.Success || result.Value is null)
         {
@@ -171,13 +202,13 @@
         var tracks = result.Value.Items.ToList();
         if (tracks.Count == 0)
         {
-            _loadError = $"No tracks found for release '{AlbumName}'.";
+            _loadError = $"No tracks found for release '{albumName}'.";
             _loading = false;
             return;
         }
 
         var release = tracks[0].Release;
-        _albumName = AlbumName;
+        _albumName = albumName;
         _artist = release?.Artist ?? string.Empty;
         _genre = release?.Genre ?? string.Empty;
         _releaseDate = release?.ReleaseDate?.ToString("yyyy-MM-dd") ?? string.Empty;
@@ -203,10 +234,24 @@
             _tracks.RemoveRange(1, _tracks.Count - 1);
         }
 
-        _selectedIndex = _tracks.Count > 0 ? 0 : -1;
+        // Track-addressed entry pre-selects the clicked row (§8.M Option 2). For a multi-track Cut
+        // the addressed track may be any ordinal; for single-track media it is always row 0 (the
+        // collapse above leaves one row). Fall back to row 0 if the id is absent or trimmed away.
+        _selectedIndex = ResolveInitialSelection();
         _loading = false;
     }
 
+    private int ResolveInitialSelection()
+    {
+        if (_tracks.Count == 0) return -1;
+        if (TrackId is { } trackId)
+        {
+            var addressed = _tracks.FindIndex(t => t.Id == trackId);
+            if (addressed >= 0) return addressed;
+        }
+        return 0;
+    }
+
     private void HandleWavFilesSelected(IReadOnlyList<IBrowserFile> files)
     {
         _errorMessage = null;
@@ -471,7 +516,7 @@
 
                                 if (!linkResult.Success)
                                 {
-                                    // Non-blocking: track persisted; cover can be linked via TrackEdit.
+                                    // Non-blocking: track persisted; cover can be re-linked by re-editing.
                                     Logger.LogWarning("Batch edit: cover link failed for new track '{TrackName}' (id={Id})",
                                         row.TrackName, uploadResult.Value.Id);
                                 }