Refactor bumper preview functionality: update API endpoints to support rendering previews for all bumper sub-blocks, modify related query and handler to generate individual asset previews, and enhance frontend components for improved user experience with variant-specific previews. Update translations for consistency in terminology.

backend/src/TeleWave.Api/Endpoints/ChannelEndpoints.cs

@@ -85,11 +85,11 @@ public static class ChannelEndpoints
             .MapPost("/{id:guid}/bumper/templates/{templateId:guid}/preview", RenderPreview)
             .Produces(StatusCodes.Status204NoContent);
         admin.MapGet(
-            "/{id:guid}/bumper/templates/{templateId:guid}/preview/index.m3u8",
+            "/{id:guid}/bumper/templates/{templateId:guid}/preview/{variantId:guid}/index.m3u8",
             PreviewPlaylist
         );
         admin.MapGet(
-            "/{id:guid}/bumper/templates/{templateId:guid}/preview/{file}",
+            "/{id:guid}/bumper/templates/{templateId:guid}/preview/{variantId:guid}/{file}",
             PreviewSegment
         );
 
@@ -452,10 +452,10 @@ public static class ChannelEndpoints
         return result.IsSuccess ? Results.NoContent() : result.ToHttpResult();
     }
 
-    /// <summary>Плейлист превью: переписываем ffmpeg-index.m3u8, направляя сегменты на admin-роут.</summary>
-    private static IResult PreviewPlaylist(Guid id, Guid templateId, MediaPathResolver paths)
+    /// <summary>Плейлист превью подблока: переписываем ffmpeg-index.m3u8, направляя сегменты на admin-роут.</summary>
+    private static IResult PreviewPlaylist(Guid id, Guid templateId, Guid variantId, MediaPathResolver paths)
     {
-        var previewId = BumperPreview.AssetId(templateId);
+        var previewId = BumperPreview.AssetId(variantId);
         string indexPath;
         try
         {
@@ -468,7 +468,7 @@ public static class ChannelEndpoints
         if (!File.Exists(indexPath))
             return Results.NotFound();
 
-        var baseUrl = $"/api/admin/channels/{id}/bumper/templates/{templateId}/preview/";
+        var baseUrl = $"/api/admin/channels/{id}/bumper/templates/{templateId}/preview/{variantId}/";
         var sb = new StringBuilder();
         foreach (var line in File.ReadLines(indexPath))
         {
@@ -483,12 +483,18 @@ public static class ChannelEndpoints
         return Results.Text(sb.ToString(), "application/vnd.apple.mpegurl");
     }
 
-    private static IResult PreviewSegment(Guid id, Guid templateId, string file, MediaPathResolver paths)
+    private static IResult PreviewSegment(
+        Guid id,
+        Guid templateId,
+        Guid variantId,
+        string file,
+        MediaPathResolver paths
+    )
     {
         if (!BumperSegmentFileName.IsMatch(file))
             return Results.NotFound();
 
-        var previewId = BumperPreview.AssetId(templateId);
+        var previewId = BumperPreview.AssetId(variantId);
         string path;
         try
         {