Add server-side waveform loudness profiling on track upload

ILoudnessAlgorithm strategy (RmsLoudnessAlgorithm first impl), WaveformProfileService
stores quantized byte[] sidecar in new MediaFileVault (profiles vault), wired into
UnifiedTrackService.UploadAsync; failure is logged and swallowed. WaveformProfileDto
and WaveformProfileOptions in shared projects.

DeepDrftAPI/Services/UnifiedTrackService.cs

@@ -1,5 +1,6 @@
 using DeepDrftContent;
 using DeepDrftContent.Constants;
+using DeepDrftContent.Processors;
 using DeepDrftData;
 using DeepDrftModels.DTOs;
 using NetBlocks.Models;
@@ -18,17 +19,20 @@ public class UnifiedTrackService
     private readonly TrackContentService _contentTrackContentService;
     private readonly ITrackService _sqlTrackService;
     private readonly FileDb _fileDatabase;
+    private readonly WaveformProfileService _waveformProfileService;
     private readonly ILogger<UnifiedTrackService> _logger;
 
     public UnifiedTrackService(
         TrackContentService contentTrackContentService,
         ITrackService sqlTrackService,
         FileDb fileDatabase,
+        WaveformProfileService waveformProfileService,
         ILogger<UnifiedTrackService> logger)
     {
         _contentTrackContentService = contentTrackContentService;
         _sqlTrackService = sqlTrackService;
         _fileDatabase = fileDatabase;
+        _waveformProfileService = waveformProfileService;
         _logger = logger;
     }
 
@@ -70,9 +74,27 @@ public class UnifiedTrackService
             return ResultContainer<TrackDto>.CreateFailResult($"Track was uploaded but could not be saved: {error}");
         }
 
+        // Best-effort waveform profile: both stores succeeded, so the upload is a success
+        // regardless of the profile outcome. A missing profile renders as a flat seekbar on the
+        // frontend, so a failure here is logged and swallowed — never fails the upload.
+        await TryStoreWaveformProfileAsync(tempFilePath, unpersisted.EntryKey, ct);
+
         return saveResult;
     }
 
+    private async Task TryStoreWaveformProfileAsync(string tempFilePath, string entryKey, CancellationToken ct)
+    {
+        try
+        {
+            var wavBytes = await File.ReadAllBytesAsync(tempFilePath, ct);
+            await _waveformProfileService.ComputeAndStoreAsync(wavBytes, entryKey);
+        }
+        catch (Exception ex) when (ex is not OperationCanceledException)
+        {
+            _logger.LogError(ex, "Waveform profile step failed for {EntryKey}; upload unaffected.", entryKey);
+        }
+    }
+
     /// <summary>
     /// Delete a track's SQL row, then its vault entry. SQL is the source of truth: a SQL delete
     /// failure fails the operation (and leaves the vault untouched), but a subsequent vault delete

DeepDrftAPI/Startup.cs

@@ -19,6 +19,12 @@ namespace DeepDrftAPI
             builder.Services.AddSingleton<AudioProcessor>();
             builder.Services.AddSingleton<TrackContentService>();
 
+            // Waveform loudness profiling (upload-time, off the playback path)
+            builder.Services.Configure<WaveformProfileOptions>(
+                builder.Configuration.GetSection(nameof(WaveformProfileOptions)));
+            builder.Services.AddSingleton<ILoudnessAlgorithm, RmsLoudnessAlgorithm>();
+            builder.Services.AddSingleton<WaveformProfileService>();
+
             // File Database
             var fileDatabasePath = CredentialTools.ResolvePathOrThrow("filedatabase", "environment/filedatabase.json");
             builder.Configuration.AddJsonFile(fileDatabasePath, optional: false, reloadOnChange: false);