Add CMS waveform pre-processing panel with backfill endpoints

GET api/track/waveform-status and POST api/track/{id}/waveform (ApiKey);
CmsTrackService methods; TrackPreProcessing page with per-row and
sequential bulk generation; nav links from TrackList and Index.

DeepDrftAPI/Controllers/TrackController.cs

@@ -72,6 +72,39 @@ public class TrackController : ControllerBase
         return Ok(result.Value);
     }
 
+    // GET api/track/waveform-status ([ApiKeyAuthorize])
+    // Admin backfill view: returns every track with a flag for whether a waveform profile is
+    // stored in the WaveformProfiles vault. The catalogue is small enough that the CMS panel reads
+    // the whole list unpaged. Declared before the parameterized "{trackId}" route so the literal
+    // segment is never treated as a trackId.
+    [ApiKeyAuthorize]
+    [HttpGet("waveform-status")]
+    public async Task<ActionResult> GetWaveformStatus()
+    {
+        var tracks = await _sqlTrackService.GetAll();
+        if (!tracks.Success || tracks.Value is null)
+        {
+            var error = tracks.Messages.FirstOrDefault()?.Message ?? "Unknown error";
+            _logger.LogError("GetWaveformStatus failed to load tracks: {Error}", error);
+            return StatusCode(500, "Failed to load tracks");
+        }
+
+        var status = new List<WaveformStatusDto>(tracks.Value.Count);
+        foreach (var track in tracks.Value)
+        {
+            var profile = await _waveformProfileService.GetProfileAsync(track.EntryKey);
+            status.Add(new WaveformStatusDto
+            {
+                TrackId = track.Id,
+                EntryKey = track.EntryKey,
+                TrackName = track.TrackName,
+                HasProfile = profile is not null,
+            });
+        }
+
+        return Ok(status);
+    }
+
     // POST api/track/upload: raw WAV in (multipart/form-data) + metadata → persisted TrackDto out.
     // Used by the CMS upload flow on DeepDrftManager; that host proxies the upload here so it never
     // touches the vault disk path or SQL directly. UnifiedTrackService owns the two-database write.
@@ -375,6 +408,32 @@ public class TrackController : ControllerBase
         });
     }
 
+    // POST api/track/{trackId}/waveform ([ApiKeyAuthorize])
+    // Admin backfill: compute and store a waveform profile for an existing track from its vault
+    // audio. trackId is the EntryKey. 404 when no audio is stored under that key; 500 when the
+    // WAV cannot be decoded or the vault write fails. Used by the CMS PreProcessing panel for
+    // tracks that predate the WaveformSeeker feature.
+    [ApiKeyAuthorize]
+    [HttpPost("{trackId}/waveform")]
+    public async Task<ActionResult> GenerateWaveform(string trackId)
+    {
+        var audio = await _trackContentService.GetAudioBinaryAsync(trackId);
+        if (audio is null)
+        {
+            _logger.LogWarning("GenerateWaveform: no audio in vault for {TrackId}", trackId);
+            return NotFound();
+        }
+
+        var stored = await _waveformProfileService.ComputeAndStoreAsync(audio.Buffer, trackId);
+        if (!stored)
+        {
+            _logger.LogError("GenerateWaveform: profile computation/storage failed for {TrackId}", trackId);
+            return StatusCode(500, "Failed to generate waveform profile.");
+        }
+
+        return Ok();
+    }
+
     [ApiKeyAuthorize]
     [HttpPut("{trackId}")]
     public async Task<ActionResult> PutTrack(string trackId, [FromBody] AudioBinaryDto track)